https://news.mcmedia.cam/feed/Condensed_Matter MCMedia News RSS Feed - Condensed_Matter specific feed https://news.mcmedia.cam/rss-info.html MCMedia RSS Generator v1.0 Fri, 17 Apr 2026 17:50:33 +0000 https://arxiv.org/abs/2512.24501 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2512.24501v2 Announce Type: replace Abstract: A model of microscopic interaction between a superconductor and a one-dimensional topological insulator, an SSH chain, is considered. Using the functional integration method, the effective action of the interaction between a superconductor and a topological insulator is obtained. We obtain corrections to the quasiparticle excitation spectrum of the SSH chain due to tunneling in various limits and discuss the influence of phase fluctuations. We find that for bulk superconductors, the states of the chain are stable for energies lying inside the superconducting gap while in lower-dimensional superconductors phase fluctuations yield finite temperature-dependent lifetimes even inside the gap. We also discuss whether these results can be reproduced within a simple phenomenological approach. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2510.24404 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.24404v3 Announce Type: replace Abstract: An interaction between ferromagnetic and superconducting orders, to be realized in a two dimensional ferromagnetic superconductor, is proposed obeying necessary symmetry principles. This interaction allows us to formulate a duality, similar to the Boson-vortex duality in 2+1 dimensional superfluid. In the dual theory the Skyrmion and the vortex excitations interact with each other via an emergent gauge field. The static interaction potential is attractive for a Skyrmion and a vortex with opposite topological charges. This interaction can lead to formation of bound pairs of the mentioned topological excitations. Furthermore, we argue that such pairing implies that a Magnus force acting on the vortex induces a transverse, Hall-like drift motion of the Skyrmion, which we term the vortex-drag induced Skyrmion Hall effect. Possible experimental manifestations of this effect are also discussed. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2501.10998 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2501.10998v2 Announce Type: replace Abstract: Kagome superconductors AV$_3$Sb$_5$ (A=K, Rb, Cs) have sparked considerable interest due to the presence of several intertwined symmetry-breaking phases within a single material. Interestingly, in a recent experiment, magnetic hysteresis was observed in the superconducting state through magnetoresistance measurements in RbV$_{3}$Sb$_{5}$ [Nature Comm \textbf{17}, 1310 (2026)], providing strong evidence of a spontaneous time-reversal symmetry breaking superconducting state. The magnetic hysteresis, combined with crystalline symmetry, imposes strong constraints on the possible pairing symmetries of the superconducting state. In this work, we propose that RbV$_3$Sb$_5$ is a nodal topological superconductor with pseudo-spin-polarized Cooper pairs. The pseudo-spin-polarized superconducting domains resemble the properties of ferromagnetic domains and induce hysteresis. Moreover, the nodal topological superconducting state possesses Majorana flat band modes at the sample boundary, which can be detected by tunneling experiments. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2411.17815 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2411.17815v3 Announce Type: replace Abstract: Superconductivity in a partially filled flat band presents a vexing conceptual hurdle because the absence of a Fermi surface precludes a weak-coupling regime where one can extend insights from the Bardeen-Cooper-Schrieffer picture of a Fermi surface instability. We approach the strongly correlated problem of flat band superconductivity from the strong coupling limit of local attractive interactions on line-graph lattices, whose non-interacting bandstructures host exactly flat bands. In this limit, the pair kinetic energy which sets the superfluid stiffness is expected to scale inversely with the pair binding interaction. Here we demonstrate a striking counterexample. We show that when doped charges propagate on the line-graph of a lattice with strong pairing interaction, they bind into obstructed Cooper pairs whose motion is frustrated by destructive interference. As a result, the leading-order pair kinetic energy vanishes identically in the strong-coupling expansion, producing a flat bosonic band of compact localized pair states, zero superfluid stiffness at leading order, and an extensively degenerate many-body ground state manifold. At quarter filling, the frustrated pair dynamics maps onto a quantum dimer model with a $d$-wave resonating-valence-bond spin liquid ground state, which becomes exact at the analytically solvable Rokhsar-Kivelson point. The pairing Hamiltonian in this limit thus has a topologically ordered ground state with long-range entanglement and deconfined holon excitations. Interestingly, we find exact compact localized eigenstates and extensive degeneracies in the many-body eigenstates of this emergent dimer model. Our results establish a disorder-free mechanism for interaction-driven localization, in which strong pairing collapses the kinetic energy of Cooper pairs. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.15204 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15204v1 Announce Type: new Abstract: We study the penetration of an external magnetic field into a superconductor with collinear $d$-wave altermagnetic order. We demonstrate that instead of circular Abrikosov vortices, the magnetic field generates elliptical vortices with their major axis oriented along one of the crystallographic axis, along which the altermagnetic spin splitting is maximal. Upon reversing the component of the magnetic field parallel to the altermagnetic N\'eel vector, the vortices reorient towards the other crystallographic axis with maximal spin splitting. We demonstrate that this effect originates from an altermagnetism-induced anisotropy of the effective mass, which is controlled by the coupling between the external magnetic field and the N\'eel vector. As a consequence, a superconducting film hosting such altermagnetic order and containing pinning defects exhibits nonreciprocal magnetization curves under reversal of the magnetic field parallel to its N\'eel vector, due to the different vortex--vortex interaction energies for the two field orientations. Our results broaden the understanding of the coexistence of altermagnetism and superconductivity, both in materials hosting these orders intrinsically or in superconductor/altermagnet hybrid structures, and open new experimental avenues for exploring supercurrent vortices in these systems. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.15120 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15120v1 Announce Type: new Abstract: We extend the well-established action of the Higgs mode in $s$-wave superconductors to include quantum fluctuations (QFs). We find that already one-loop quantum corrections to the Higgs propagator shift its eigenfrequency below the superconducting energy gap $2\Delta$. Consequently, the Higgs mode appears as an undamped pole below the quasiparticle continuum, leading to drastically sharper experimental signatures. We demonstrate this by calculating two characteristic fingerprints of the Higgs mode, namely in Third Harmonic Generation (THG) and inelastic Raman scattering signals. More generally, gaps measured in $s$-wave superconductors with different experimental techniques (such as scanning tunneling microscope and Raman scattering) may be different due to fluctuation corrections. Since already arbitrarily weak QFs lead to the shift and to the new pole, our results shed some light on other amplitude modes even for systems with weak QFs, including charge density waves, (anti-) ferromagnets, or cold atom fermionic condensates. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.15054 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15054v1 Announce Type: new Abstract: Lifshitz invariant is a symmetry-allowed term in the Ginzburg-Landau free energy of an ordered phase, involving the order parameters and a single spatial derivative, which serves as a source of unusual optical responses. Here we introduce a ``type II" Lifshitz invariant for superconductors, which changes its sign under the particle-hole transformation and can be distinguished from the ordinary particle-hole even ``type I" Lifshitz invariant. We show that the type II Lifshitz invariant appears only in superconductors that break time-reversal symmetry and allows the Higgs mode to be visible in the optical conductivity spectrum. We provide a classification of all pairs of irreducible corepresentations of order parameters in the magnetic point groups that admit a type II Lifshitz invariant. We also numerically calculate the optical conductivity for various models of time-reversal symmetry broken multiband superconductors, finding agreement with the group-theoretical analysis. Our results establish a universal class of time-reversal symmetry broken superconductors hosting an optically active Higgs mode. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14623 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14623v1 Announce Type: new Abstract: This study maps the quantum landscape of superconducting diodes (SDs) \cite{nadeem23} onto the quantum technology architecture, which is currently constrained by fundamental challenges in control and scalability. In the existing non-integrated quantum technology hardware, control and scalability related issues emerge at two fronts: First, nonlinear and nonreciprocal circuit elements, which are essential building blocks for quantum processors, are often complex, bulky, and dissipative. Second, the temperature gradient between classical control electronics ($T_C\gtrsim$ K), which is also dissipative, and the quantum processor at cryogenic temperatures ($T_Q\sim$ mK) makes scalability even more challenging. The main focus is to reveal how the built-in nonlinearity, nonreciprocity, and quantum functionalities of SDs are significant for on-chip integrated circuit quantum electrodynamics (c-QED), enabling scalable integration of noise-resilient qubit and qubit-interfaces for efficient power delivery, coherent control and memory, high-fidelity readout, and quantum-limited amplification. To this end, this study will also shed light on how thermodynamic constraints and field effects can be harnessed within a quantum-enhanced SD platform, thereby enabling thermal compatibility between classical and quantum workflows, isothermal all-electrical control, and on-chip scalability. This perspective is expected to play a pivotal role in the advancement of superconducting circuit-based quantum hardware with temperature-matched classical, quantum, and hybrid workflows. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14578 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14578v1 Announce Type: new Abstract: Understanding and controlling vortex motion in superconductors are important both for suppressing dissipation in superconducting devices and for device applications that exploit vortices. In this work, we quantitatively imaged the stray magnetic field distribution of vortices in an NbN thin film by wide-field magnetic imaging using a perfectly aligned diamond NV ensemble. By continuously measuring while stepwise varying the applied magnetic field under local laser heating, we captured a rearrangement of the vortex configuration in real space and in real time over more than 100 min. The observed vortex rearrangement is consistent with a reduction of the pinning force due to local laser heating and with the Lorentz force exerted by shielding currents induced by the field variation. These results provide insight into vortex dynamics and suggest potential applications, including vortex exclusion from sensitive regions of superconducting devices and vortex positioning in vortex-based devices. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14485 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14485v1 Announce Type: new Abstract: We demonstrate a rapid, maskless fabrication method for superconducting terahertz Josephson plasma emitters (JPEs) based on direct ultraviolet laser micromachining of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi-2212) single crystals. Although machining debris is formed near the processed regions, uniform stacks of intrinsic Josephson junctions are preserved inside the crystal, enabling stable terahertz emission. Devices fabricated with Ag, Cu, and Cr electrodes all exhibited terahertz radiation, with Cu electrodes showing performance comparable to Ag while offering a low-cost alternative. Spectroscopic and polarization analyses indicate that the emitted radiation is elliptically polarized and dominated by the geometrical cavity resonance mode. Structural and electrical characterizations reveal that the machining width and depth are not limited by the optical spot size but are governed by the anisotropic thermal conductivity of Bi-2212, consistent with a thermally dominated laser ablation process. This direct laser micromachining approach provides a fast and versatile fabrication technique for JPEs and is broadly applicable to superconducting electronics and terahertz devices. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14395 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14395v1 Announce Type: new Abstract: We previously reported apparent ideal diamagnetism at ambient conditions in a graphene-n-heptane-permalloy system. At the same time, the experiments revealed inconsistent behavior, including signal freezing and occasional paramagnetic responses. Further measurements performed without graphene produced similar signals, indicating that graphene is not responsible for the observed effects. The results suggest that magnetic field redistribution caused by inhomogeneities in the permalloy foil and experimental geometry can mimic ideal diamagnetism in sub-milligauss measurements. These findings revise the interpretation of our earlier results and emphasize caution in interpreting ultra-low-field magnetic measurements. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2512.14414 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2512.14414v2 Announce Type: replace Abstract: We propose a single-layer tensor network framework for the variational determination of ground states in two-dimensional quantum lattice models. By combining the nested tensor network method [Phys. Rev. B 96, 045128 (2017)] with the automatic differentiation technique, our approach can reduce the computational cost by three orders of magnitude in bond dimension, and therefore enables highly efficient variational ground-state calculations. We demonstrate the capability of this framework through two quantum spin models: the antiferromagnetic Heisenberg model on a square lattice and the frustrated Shastry-Sutherland model. Even without GPU acceleration or symmetry implementation, we have achieved a bond dimension of nine and obtained accurate ground-state energy and consistent order parameters compared to prior studies. In particular, we confirm the existence of an intermediate empty-plaquette valence bond solid ground state in the Shastry-Sutherland model. We have further discussed the convergence of the algorithm and its potential improvements. Our work provides a promising route for large-scale tensor network calculations of two-dimensional quantum systems. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2511.06004 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2511.06004v2 Announce Type: replace Abstract: The ground state of the classical antiferromagnetic XX model in a magnetic field is calculated for spins mounted on the vertices of the icosahedron. The magnetization is characterized by two discontinuities as a function of the external field. For a wide field range above the first discontinuity the ground state is degenerate, with two spins related by spatial inversion aligned with the field and the rest forming two magnetization units in the form of pentagons. It is shown that the degeneracy originates from the coupling of the two pentagons, which introduces the triangle, associated with ground-state degeneracy, as an interaction unit in the icosahedron. The magnetization discontinuities are shown to evolve first from the coupling of isolated triangles and then from the coupling of the two spins related by spatial inversion. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.11678 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.11678v2 Announce Type: replace Abstract: The kagome lattice of spin-1/2 copper atoms in herbertsmithite is conjectured to sustain a quantum spin liquid state with spinon quasiparticles. Ideally, the kagome crystal planes are each separated by a plane of spinless zinc atoms. However, in real crystals some spin-1/2 copper atoms substitute randomly onto these inter-kagome zinc sites. Here we reconceptualize such 'impurity' atoms as quantum witness spins whose dynamics is designed to probe the spin liquid state. We then introduce spin noise spectroscopy to measure the frequency and temperature dependence of witness spin dynamics, demonstrating that their phenomenology is consistent with extensive interactions between witness spins mediated by propagation of spinons through a quantum spin liquid. Ultimately, a sharp transition occurs at around 260 mK, below which the properties of both spin noise and magnetic susceptibility suggest that the witness spins form a spin glass phase. Among theoretical models considered, we demonstrate that our observations are only consistent with spinon-mediated interactions between witness spins by either a Z2 or U(1) quantum spin liquid, with the former model more closely matching the data. Our work demonstrates that quantum mechanical witness spins may now conceivably be used as a widely applicable probe of quantum spin liquid physics. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.03967 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.03967v2 Announce Type: replace Abstract: We extend a recently defined measure of symmetry breaking, the entanglement asymmetry, to higher-form symmetries. In particular, we focus on Abelian topological order in two dimensions, which spontaneously breaks a 1-form symmetry. Using the toric code as a primary example, we compute the entanglement asymmetry and compare it to the topological entanglement entropy. We find that while the two quantities are not strictly equivalent, both are sub-leading corrections to the area law and can serve as order parameters for the topological phase. We generalize our results to non-chiral Abelian topological order and express the maximal entanglement asymmetry in terms of the quantum dimension. Finally, we discuss how the scaling of entanglement asymmetry correctly detects topological order in the deformed toric code, where 1-form symmetry breaking persists even in a trivial phase. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2505.21054 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2505.21054v3 Announce Type: replace Abstract: We present an iterative method for generating the complete set of self-energy Feynman diagrams at arbitrary order for the single-polaron problem with arbitrary linear coupling to the lattice. The approach combines a combinatorial representation of noncrossing diagrams, based on Dyck paths associated with Stieltjes-Rogers polynomials, with the constraints of the Ward-Takahashi identity to systematically incorporate vertex corrections. This construction yields a one-to-one correspondence between terms in the expansion based on Stieltjes-Rogers polynomials and diagrammatic contributions, and provides, through a sequence of simple steps, a closed, algorithmic framework for generating all diagrams of a given order, together with their relative weights. The method enables efficient, unbiased evaluation of diagrammatic series and improves the convergence of diagrammatic Monte Carlo by eliminating the need for stochastic weighting between different topologies. We further outline how the construction can be generalized to finite-density electron systems. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2504.06739 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2504.06739v3 Announce Type: replace Abstract: Kondo screening of local moments in normal metals typically leads to hybridized conduction and valence bands separated by a Kondo gap, resulting in an insulating state at half-band filling. We show a dramatic change of this scenario in a Dirac-semimetal-based correlated system -- a bilayer honeycomb lattice heterostructure where a local moment lattice is stacked on a Dirac semimetal breaking the inversion symmetry. This system is modeled by an extended Anderson honeycomb lattice involving the real-space dependence of major interlayer hybridization parameters on the relative sliding distance along the armchair direction. First, we unveil multiple Kondo scales and successive Kondo breakdown transitions in this correlated heterostructure under sliding. Second, we demonstrate the existence of a genuine selective Kondo screening phase which is stabilized near the A-B stack pattern and is accessible by applying interlayer voltage. Third, we find a nearly flat hybridized band located concomitantly within the Kondo gap, resulting in an unprecedented metallic state at half-band filling. This unconventional heavy fermion state is characterized by violation of Luttinger theorem and appearance of a Van Hove singularity at the Fermi energy. The general sliding-driven band structure landscape and the implications of our results for the broad context of multiorbital Kondo physics are briefly discussed. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14952 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14952v1 Announce Type: cross Abstract: The question of a possible quantum critical point lying inside of a superconducting phase is central for understanding unconventional superconductivity. In various unconventional superconductors, non-Fermi-liquid/'strange-metal' $T^{n}$ variations, with $n<2$, of the electrical resistivity have been identified as the signature of magnetic quantum criticality. However, a difficulty is to prove experimentally that a non-Fermi-liquid/'strange-metal' law identified at temperatures above the superconducting temperature is the signature of an intrinsic zero-temperature quantum critical regime. In the heavy-fermion paramagnet UTe$_2$, unconventional superconductivity develops in the vicinity of a metamagnetic quantum phase transition induced by a magnetic field, and the quantum critical magnetic properties are suspected to play a role for the superconducting mechanism. In this work, we present a comparative analysis of electrical resistivity data collected on two UTe$_2$ samples of different qualities, in magnetic fields tilted by angles $\theta\simeq35-40$~$^\circ$ from $\mathbf{b}$ to $\mathbf{c}$. Fits to the data have been performed either with a Fermi-liquid function $\rho=\rho_0+AT^{2}$ or with a non-Fermi-liquid/'strange-metal' function $\rho=\rho_0+A_nT^n$. Near to a superconducting phase induced beyond 40~T, non-physical residual resistivities $\rho_0<0$ are extracted from the $T^n$ fits, revealing that a 'hidden' Fermi-liquid $T^2$ regime may be ultimately recovered at low temperature. The results obtained here highlight the importance to investigate high-quality samples with low residual resistivity to confirm - or not - the presence of a suspected 'hidden' quantum critical behavior masked by superconductivity. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14701 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14701v1 Announce Type: cross Abstract: Ruddlesden-Popper nickelates offer a new route to high-temperature superconductivity beyond the cuprates and iron-pnictides. However, the electronic reorganization that enables superconductivity in bilayer nickelates remain unresolved, largely due to the difficulty of directly probing the superconducting phase. Here, we overcome this limitation by stabilizing superconducting (La,Pr)$_3$Ni$_2$O$_7$ thin films with a protective capping layer, thereby enabling direct spectroscopic access via X-ray absorption and resonant inelastic X-ray scattering. We resolve the evolution of in-plane and out-of-plane electronic states, spin and orbital excitations, and spin-density-waves across insulating, superconducting, and metallic regimes. Combining experimental results with theoretical analysis, we show that the in-plane $d_{x^2-y^2}$ states form an itinerant backbone, while superconductivity emerges only when coherent $d_{z^2}$-$p_z$-$d_{z^2}$ interlayer hybridization develops, accompanied by suppressed static spin order and strongly damped spin excitations. Oxygen stoichiometry and epitaxial strain both act on this interlayer channel, placing superconductivity within a narrow window of interlayer coherence and correlation strength. These findings identify the microscopic ingredients required for superconductivity in bilayer nickelates and provide a multiorbital picture of its emergence. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14859 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14859v1 Announce Type: new Abstract: Plasmon modes, their dispersion, and the onset of damping when approaching the electron-hole continuum are well understood when electron correlations are weak. However, we know little about how this picture is modified and what additional features emerge in strongly correlated materials. Here, we present a fully ab initio approach to plasmon excitations that combines density functional theory with dynamical mean-field theory, and we use it to reconcile controversial electron energy-loss spectroscopy results in Sr$_2$RuO$_4$. In particular, we show that electronic correlations reproduce the plasmon dispersion, while generating a large intrinsic width already below the electron-hole continuum. An additional high-energy peak reflecting transitions between incoherent features and a sharp increase of the plasmon's energy-momentum dispersion, akin to waterfalls in photoemission spectroscopy, are identified as genuine correlation effects. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14767 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14767v1 Announce Type: new Abstract: We investigate the ground-state magnetic structure of the spin-$1/2$ XXZ antiferromagnet on the triangular lattice in the easy-axis regime using the density-matrix renormalization group. By applying spiral boundary conditions, we exactly map finite $L\times L$ clusters onto one-dimensional chains while avoiding the spatial anisotropy inherent in cylindrical geometries. From symmetry-broken local magnetization profiles, we extract the three-sublattice moments and track their evolution with anisotropy. At the isotropic point, we obtain a positive sublattice moment of $0.21671$, consistent with previous numerical estimates. In the easy-axis regime, the ordered moments remain close to a zero-magnetization three-sublattice structure of the form $(2m,-m,-m)$ over a broad range of $\Delta$. Extrapolation in $1/\Delta$ shows that the positive sublattice moment stays well below the classical saturation value $1/2$, approaching $0.41873$ as $\Delta\to\infty$, while the magnitude of the negative sublattice moment approaches $0.20832$. We further compare the energies of the Y state and the up-down-down state and find that the Y state is favored at zero field. Independent thermodynamic-limit energy calculations, performed without assuming any particular ordered pattern, yield an energy consistent with the Y-state solution. These results show that the easy-axis ground state does not simply cross over to a trivially saturated collinear Ising state, but instead remains a nontrivial three-sublattice ordered state selected from the macroscopically degenerate Ising manifold by quantum fluctuations. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14695 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14695v1 Announce Type: new Abstract: Understanding how the interaction range and various types of disorder affect the level statistics of many-body quantum systems and lead to the emergence of many-body localization (MBL) is a challenging open frontier. We study the level statistics of a variant of the spin-$1/2$ Haldane-Shastry model with $1/r^{\alpha}$ interactions, where $\alpha{\geq}0$ parametrizes the range of the interactions, in the presence of position disorder and/or random magnetic fields. We find that neither position disorder nor random magnetic fields alone yields pristine Poisson statistics in this long-range interacting system; however, Poisson statistics emerge in their combined presence, suggesting the emergence of MBL when both types of disorder coexist. Interestingly, once random magnetic fields break the $SU(2)$ symmetry, the strength of the position disorder, $\delta$, appears to play an important role, as evidenced by an approximate scaling collapse of the disorder-averaged gap ratios that is parametrized in terms of a single parameter, $\alpha \delta$. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14415 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14415v1 Announce Type: new Abstract: Correlated transition metal oxides present exciting prospects as switches or memory and storage devices owing to the possibility to control electronic properties using various external stimuli. While their complex behaviour is known to stem from interplay between electronic correlations, atomic structure and orbital physics, they remain poorly understood on the microscopic level. Here, we investigate such origins as a function of temperature and pressure in the transition metal oxide Ti3O5. We find that the insulating room-temperature phase is characterized by one-dimensional zig-zag chains composed by two types of titanium dimers forming orbital selective valence bonds. At the thermal phase transition, one type of titanium dimer breaks up, resulting in an insulator to metal transition with a large orbital repopulation between the two states. Moreover, optical spectroscopy reveals that an additional pressure-driven insulator to metal transition occurs in Ti3O5 at room temperature. The phenomenology of this novel pressure-induced metallic transition is completely different from the insofar studied transitions and results from a competition between intra- and inter-dimer hopping. Our combined results suggest that Ti3O5 is a prototypical correlated transition metal oxide, where both correlations as well as orbital interactions need to be considered to fully understand the evolution of the electronic states. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14369 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14369v1 Announce Type: new Abstract: Twisted bilayer graphene provides a paradigmatic platform for exploring the interplay between electronic topology and strong correlations. Within the topological heavy fermion model [Song and Bernevig, Phys. Rev. Lett. 129, 047601 (2022)], topology and electron interactions are brought together by including a weak hybridization between the bands of itinerant $c$- and localized $f$-electrons. Hybridization infuses concentrated Berry curvature into the $f$-band, while leaving it flat. These band features have motivated recent proposals of a Mott semimetal phase above the flavor-ordering temperature at charge neutrality. In this work, we develop an analytic theory of the quasiparticle dispersion and lifetime in the Mott semimetal. We reformulate the interacting flat-band Hamiltonian as an on-site Hubbard interaction defined on a set of non-orthogonal orbitals, and compute the electron Green's function using the equation-of-motion method, in close analogy with the Hubbard-III approximation. Unlike the conventional Hubbard model, in our case this approximation is controlled by a well-defined small parameter in the theory. We evaluate the electron self-energy and demonstrate the emergence of well-defined low-energy quasiparticles with the dispersion and relaxation rate proportional to the interaction strength. The quasiparticle spectrum is well-resolved in energy and in momentum down to the very vicinity of the Fermi level. Our results illustrate unconventional spectral properties arising from strong correlations and nontrivial quantum geometry, and have direct relevance for spectroscopic probes such as quantum twisting microscope experiments. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14367 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14367v1 Announce Type: new Abstract: We develop a general framework to calculate the many-body density of states (DOS) of isolated and interacting quantum systems. Based on the generalized coherent state formalism and the Simon-Lieb bounds for a quantum partition function, our method provides a general method of calculation for the DOS in high-dimensional irreducible sectors. This framework further provides rigorous bounds for the ground state energy in each sector and enables the calculation of microcanonical observables across the entire spectrum. Using the Lipkin-Meshkov-Glick (LMG) model as a test bed, we validate our framework by successfully identifying quantum phase transitions (QPTs) and excited-state quantum phase transitions (ESQPTs) across spin sectors. Unlike existing model-specific numerical or analytical techniques, our formalism relies on general underlying symmetries, making it broadly applicable. Applying our method to the ferromagnetic transverse field Ising chain with power law interactions, we demonstrate that its highest-spin-sector DOS is qualitatively identical to that of LMG-type Hamiltonians. Our work establishes a versatile and computationally efficient bridge between algebraic structure and many-body thermodynamics. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14303 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14303v1 Announce Type: new Abstract: Twisted bilayer graphene near integer fillings hosts correlated single-particle excitations whose dispersion and linewidth are increasingly accessible experimentally. We study these excitations using the topological heavy-fermion model, which captures both strong correlations and band topology of twisted bilayer graphene. In the decoupled limit, where both the single-particle fc hybridization and the Hund coupling between f and c electrons are absent, the model admits exact solutions in which free Dirac fermions coexist with interacting f electrons that form zero-width Hubbard bands. By treating the fc hybridization and Hund coupling perturbatively around this solvable limit, we obtain analytical results for the single-particle self-energy. From the resulting self-energy, we derive explicit expressions for both dispersion renormalization and scattering rates of both Hubbard-band excitations and low-energy Dirac modes, thereby establishing an analytical framework for understanding correlated excitations in twisted bilayer graphene. We analyze the scattering of the two kinds, Gamma3 and Gamma1,2, of Dirac electrons and find that they arise from different mechanisms. We also briefly investigate the effect of strain. Finally, we compare these analytical expressions with DMFT results for the same model. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14295 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14295v1 Announce Type: new Abstract: In many strongly correlated electron systems, non-Fermi liquid behavior and unconventional superconductivity can be viewed as emerging from an effective 4-fermion interaction with a singular frequency dependence. A pairing instability in such a system is qualitatively different from that in a Fermi liquid and generally gives rise to multiple pairing states with topologically distinct gap functions. However, in the systems studied so far, a topologically trivial solution has the lowest energy. Here we show that a repulsive Hubbard-type interaction with a finite cutoff added to a model with a singular dynamical interaction selects, in some parameter range, the theretofore subleading, topologically nontrivial solution. We consider a minimal model that displays this behavior and show that the transformation between the topologically trivial and nontrivial gap functions necessarily occurs via an intermediate phase with topology-induced breaking of time-reversal symmetry. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14294 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14294v1 Announce Type: new Abstract: The Migdal-Eliashberg theory (MET) describes electrons interacting with phonons in the adiabatic limit when the phonon Debye frequency is much smaller than the Fermi energy. A conventional belief is that MET holds even at strong coupling, when electron self-energy is large, and breaks down only near the point where the dressed phonon spectrum softens to near zero. We analyze numerically and analytically a different option -- collapse to a polaronic/bipolaronic ground state. The last scenario has never been analyzed in precise quantitative terms for a generic electron density. Using variational considerations, we establish rigorous upper bounds on the coupling $\lambda$, at which a FL state transforms into the bipolaron/polaron state. We show that at small and near-maximum densities, this happens well before a dressed phonon softens. This is true both in 2D and 3D systems; in the latter the upper bound on $\lambda$ tends to zero in the limit of small or near-full density. We present analytical reasoning for this behavior based on hints extracted from exact diagrammatic treatment of the on-site Holstein model for the spin polarized case and argue that polarons are produced by fermions with energies comparable to the bandwidth; i.e., polaron formation is outside the realm of MET. Closer to half-filling, the leading instability upon increasing $\lambda$ is towards a charge-density-wave state (CDW), and there exists a strong coupling regime of MET near this instability, while the polaron/bipolaron state develops at larger $\lambda$ out of a CDW-ordered state and inherits a CDW order over some range of coupling. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14293 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14293v1 Announce Type: new Abstract: It is widely believed that in an adiabatic limit a Fermi liquid state of an electron-phonon system described by Migdal-Eliashberg theory remains stable before a dressed phonon softens. Using Holstein model as a prototypical example and variational/analytic considerations we demonstrate that in a wide range of fillings both in 3D and 2D, a polaronic/bi-polaronic state emerges before phonon softening; at small filling in 3D this happens already at weak coupling. We show that a polaronic/bi-polaronic state emerges, upon increasing coupling, via an intermediate pseudogap-type mixed state, in which some fermions regain Fermi liquid behavior, yet Luttinger theorem is broken. At even larger couplings the density of states gradually approaches its form in the atomic limit. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14289 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14289v1 Announce Type: new Abstract: Unlike conventional charge-2e superconductors, a charge-4e superconductor exhibits long-range coherence of electron quartets rather than Cooper pairs. Clear zero-temperature realizations of charge-4e superconductivity remain rare. Here, we investigate the zero-temperature phase diagram of the attractive SU(4) Hubbard model with numerically exact, large-scale quantum Monte Carlo (QMC) simulations overcoming major technical hurdles. We identify both charge-2e and charge-4e superconducting phases. Upon increasing interaction, charge-2e correlations are suppressed and eventually vanish, while the charge-4e correlations remain robust and converge with system size, signaling the onset of a quartet-condensed phase. Interestingly, across the charge-2e--charge-4e transition, single electrons remain gapped, while charge-2e correlations exhibit a scaling behavior inconsistent with a conventional Landau description. These features are naturally captured by a fractionalized framework in which the physical charge-2e order parameter is a composite field coupled to an emergent non-Abelian gauge structure. We formulate an Sp(4) gauge-Higgs theory that realizes deconfined quantum pseudocriticality between the Higgs (charge-2e) phase and the confined (charge-4e) phase. The Sp(4) gauge-Higgs theory yields pseudocriticality through a fixed-point collision, and its one-loop collision-point exponents quantitatively track the QMC results. Our results establish charge-4e superconductivity as a bona fide zero-temperature phase, provide a simple model for future studies in a numerically exact framework, and reveal an unconventional route to superconducting criticality. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14286 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14286v1 Announce Type: new Abstract: We show that the spin conductivity of a metal approaching a ferromagnetic quantum critical point exhibits divergent fluctuation corrections. This effect arises from critical spin fluctuations and constitutes a spin analog of the Aslamazov-Larkin theory of paraconductivity in superconductors. The spin current is derived in linear response within a Gaussian-level treatment of the effective action for a system with easy-plane magnetic anisotropy. We demonstrate the consistency of our spin transport theory by showing that it (i) fulfills the Ward identity and (ii) yields vanishing spin stiffness in the normal state. The critical enhancement of the spin conductivity is interpreted as incipient spin superfluidity in the quantum critical region. This is further supported by an intuitive picture based on the current-loop representation of the easy-plane ferromagnet. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.03796 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.03796v2 Announce Type: replace Abstract: We investigate the formation of bound states between dark-antidark solitary waves in two-component dipolar Bose-Einstein condensates. The excitation spectrum contains density and spin branches, and a rotonic feature of the spin branch enables long-range soliton interactions, giving rise to multiple bound states for a single pair, each with a distinct separation. We show that these bound states originate from periodic modulations of the inter-soliton potential, while individual solitons are surrounded by spatial spin-density oscillations. Both features provide direct signatures of the spin roton. Collisions between unbound solitons probe this potential, with dipolar interactions enforcing universal bouncing at low velocities, independent of soliton sign, whereas nondipolar solitons may either transmit or bounce. This distinct behavior offers a realistic path to confirming spin rotons experimentally. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.15234 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15234v1 Announce Type: cross Abstract: Magnetic correlations of doped Mott insulators hold the key to the unusual characteristics of many quantum materials. Recent experiments with ultracold atoms in optical lattices have provided new information about the magnetic properties of the Fermi-Hubbard model on a square lattice. We demonstrate that recent measurements indicate that a single doping-dependent energy scale determines both static correlations and dynamical response of these systems. To understand these experimental findings, we employ a self-consistent formalism to describe the coupling between antiferromagnetic magnons and doped holes, and we uncover the emergence of a universal magnetic energy scale at finite doping, which we denote by $J^*$. We present the single- and two-magnon spectral properties at finite doping and discuss the appearance of a bimagnon peak in lattice-modulation spectroscopy, at frequencies set by $J^*$. Furthermore, we argue that this same energy scale sets the onset of pseudogap phenomena, leading to the hypothesis $k_BT^* = c J^*$, with $c$ an order one number. We identify another low-energy scale emerging from our analysis of magnetic excitations, and argue that it controls the stability of N\'{e}el order at the lowest temperatures, ultimately driving a transition to an incommensurate spin-density-wave at finite doping. We discuss the relation between this low-energy scale and the nature of fermionic quasiparticles. Our analysis suggests that stability of the commensurate antiferromagentic phase at finite doping can be controlled experimentally by introducing additional quasiparticle broadening via disorder or low-frequency noise. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.15056 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15056v1 Announce Type: cross Abstract: The condensation of electron quartets, known as charge-4e superconductivity (SC), represents a novel quantum state of matter beyond the standard paradigm of Cooper pairing. However, concrete microscopic models realizing this phase in two dimensions remain a central challenge. Here, we introduce a non-engineered and sign-problem-free model, unambiguously demonstrating the emergence of a robust and high-temperature charge-4e SC phase using unbiased quantum Monte Carlo simulations. At zero temperature, the phase diagram reveals that charge-4e SC is the primary ground state in the strong-coupling regime. At finite temperature in the absence of charge-2e SC, we identify charge-4e SC through a Berezinskii-Kosterlitz-Thouless transition, marked by a universal jump in the superfluid stiffness consistent with a condensate of charge 4e. Remarkably, the transition temperature Tc increases nearly linearly with interaction strength, providing a robust mechanism for high-Tc quartet superconductivity. Furthermore, spectral analysis reveals a prominent pseudogap above Tc arising from strong phase fluctuations. Our results establish a canonical and numerically exact model system for charge-4e superconductivity, offering crucial guidance for its realization in experimental platforms such as moir\'e materials and ultracold atomic systems. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14721 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14721v1 Announce Type: cross Abstract: The Casimir-Polder (CP) effect -- the force between a neutral atom and an uncharged conducting plate in empty space -- is an intriguing consequence of quantum vacuum fluctuations. The typically attractive CP potential crosses over from a scaling of $z^{-3}$ at short separations to $z^{-4}$ at long distances, where retardation effects due to the finite speed of light become important. At intermediate distances, where the atom--surface separation is of the order of the wavelength of the dominant atomic transition, experiments have so far relied on indirect methods, such as diffraction or quantum reflection, to observe the CP effect. Here, we directly reveal the CP force between strontium atoms and a dielectric surface via the induced shifts in the atomic energy levels in the intermediate regime. We spectroscopically probe the CP-induced kHz-frequency shift of ultracold atoms confined by a magic-wavelength optical lattice at 189(2)~nm from the surface -- on the scale of the dominant 461-nm transition. Our measurements agree well with QED calculations and differ from the short-range approximation, while excluding the long-distance one. This paves the way for studying the CP effect across various surface properties and geometries, as well as exploring the tensor nature of the atom-surface potential -- all important for the development of hybrid atomic optical-magnetic quantum devices. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.15095 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15095v1 Announce Type: new Abstract: Kardar-Parisi-Zhang (KPZ) scaling has been observed in discrete polariton lattices, enabled by engineered band structures that stabilize the condensate. Whether this universality extends to intrinsically continuous systems with natural noise regularization remains an open question. We propose and numerically demonstrate KPZ scaling in a continuous quasi-one-dimensional polariton condensate stabilized by optical confinement in the transversal direction. Large-scale simulations of the stochastic Gross-Pitaevskii equation, with experimentally relevant parameters, reveal temporal and spatial scaling exponents of the two-point phase correlation function betaC = 0.30(5) and alfaC =0.46(8), and Tracy-Widom one-point phase fluctuation statistics, yielding robust KPZ dynamics intrinsic to the continuous polariton fluid. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14771 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14771v1 Announce Type: new Abstract: The plethora of possible ground states of spinor bosons placed in an external lattice and a cavity is revisited. We discuss the simplest case when the external lattice nodes coincide with the antinodes of the cavity field. We analyze the problem within the grand-canonical mean-field approach, considering both the homogeneous system and the nonhomogeneous case with a harmonic trapping potential. Due to the spin degree of freedom, in the homogeneous case we treat the system in a twofold manner: we impose the physically relevant total-magnetization constraint, while also discussing the minimization landscape for the full unconstrained problem. In the latter, by combining analytical arguments with numerical calculations based on the Gutzwiller ansatz, we show that the system exhibits two types of magnetic phases: an antiferromagnetic Mott insulator (AFM) and a ferromagnetic density wave (FDW). In addition, three distinct supersolid phases emerge, characterized by different patterns of spin and density imbalances. In case of the zero total magnetization, only two of the three supersolid regimes survive, and the FDW phases are replaced by entangled density waves (EDW). These new ground states present density-modulated superpositions of the underlying spin components of the bosons. Finally, we present the phase diagram of the trapped system, which is directly relevant for future experiments. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14559 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14559v1 Announce Type: cross Abstract: Chitosan is a highly versatile and sustainable polymer with a broad range of potential biological and materials engineering applications. Despite its versatility, the native brittleness of chitosan limits its broader utilization. This limitation can be addressed by blending chitosan with small-molecule additives to modulate its thermomechanical properties. We employ molecular dynamics (MD) simulations to investigate the mechanism underlying antiplasticization followed by plasticization at increasing water content. Decomposition of the elastic moduli reveals a competition between weakened polymer-polymer interactions and enhanced polymer-water interactions, with their relative strengths governing the resulting properties. We introduce a simple model incorporating dynamically accessible free volume regions as a key driver of polymer mobility, effectively capturing the (anti-)plasticization of elastic properties. We show that accessibility of free volume regions is enabled by connectivity of additive-accessible volume regions. This study provides new insights into the molecular interactions that dictate the properties of chitosan-water mixtures and may inform the rational design of chitosan-based materials and other hydrated biopolymers. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14183 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14183v1 Announce Type: cross Abstract: Thermal conductivity of Earths lower mantle controls heat transfer across the core-mantle boundary (CMB) and strongly influences mantle convection. We report direct measurements of the thermal conductivity of single-crystal ferropericlase (Mg$_{1-x}$Fe$_x$O, $x = 0.09$-0.13), the second most abundant lower-mantle mineral, using optical laser flash and X-ray free-electron laser heating in diamond-anvil cells up to $\sim2200$~K and 130~GPa. These experiments provide the first conductivity data for ferropericlase at simultaneous lower-mantle pressures and temperatures. A marked reduction in conductivity between 60 and 100~GPa at $\sim1700$~K is consistent with the iron spin crossover. Combined with our previous results for Fe- and Fe,Al-bearing bridgmanite, the data define a lower-mantle conductivity profile that increases with pressure to $\sim10$~W\,m$^{-1}$\,K$^{-1}$ near the CMB, constraining mantle heat flux, plume buoyancy, and long-term geodynamic evolution. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15175 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15175v1 Announce Type: new Abstract: By applying our methodology, we propose a defect in 4H-SiC which combines a Si vacancy and a C atom substituted with S (VSiSC) to have a spin-triplet ground state with the spin qubit functionality. Our calculations confirm that all configurations of the defect have a dynamically and thermodynamically stable triplet ground state and higher energy singlet states, essential for the spin-qubit polarization cycle. From GW calculations, we found that the electronic states associated with the defect form sharp and isolated peaks within the band gap for both triplet and singlet states. Further Bethe-Salpeter-equation calculations show that all considered configurations have intense optical excitations in the near infrared spectrum range. Analysis of the excitation energies and rates indicate that the VSiSC defect can be an excellent optically controlled spin qubit. Crucially, the host elements and the dopant have high-abundance isotopes with zero nuclear spin ensuring high spin-coherence time of the qubit. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15156 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15156v1 Announce Type: new Abstract: In this study, we present a comprehensive analysis of the Raman active phonon modes in orthorhombic LaInO$_3$ based on a combination of polarization-angle resolved Raman spectroscopy and density functional theory calculations. By using backscattering from multiple crystallographic surface orientations and employing a full symmetry analysis, we identify and assign most of the Raman-active $\Gamma$-point phonons to their irreducible representations of the D$_{\rm{2h}}$ point group. A multidimensional hyperspectral fitting procedure allows us to extract the relative Raman tensor elements from the angular dependence of the scattering intensities, even for strongly overlapping modes. First-principles calculations yield the phonon dispersion along high-symmetry directions, the phonon densities of states, and atomic displacement patterns, which are found to be in good agreement with the experimental mode frequencies. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15131 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15131v1 Announce Type: new Abstract: A limited remanent polarization (Pr) in HfO2-based FeRAM remains a key obstacle to density scaling and reliability, while material and process optimizations offer only incremental improvements. This limitation fundamentally originates from the thickness-constrained switchable polarization and the intrinsic polarization ceiling of HfO2-based ferroelectrics. Here, we propose an all-ALD-grown vertical complementary FeRAM (VCF) architecture, in which the top and bottom stacked FeRAM cells maintain complementary polarization. This complementary dipole configuration converts the readout from a single-layer polarization response into a differential polarization summation, thereby amplifying the effective charge window without increasing the switching field of each individual layer or incurring area overhead. Viewed from top to bottom, an "up-down" polarization pair stores logic '1', whereas a "down-up" pair stores logic '0'. Using a complementary polarization write-read scheme, the VCF achieves an effective differential polarization above 100 uC/cm^2 and retains above 90 uC/cm^2 after 1e10 switching cycles without electrical breakdown. Robust retention (longer than 1e4 s at 85 degC) and strong disturb immunity are demonstrated, with an effective differential polarization above 80 uC/cm^2 under a V/3 scheme after 1e6 disturb pulses. Array-level operation is validated in a 5 x 5 selector-free crosspoint array. The performance enhancement of the VCF arises from the co-optimization of the all-ALD-grown process, device architecture, and operation scheme, enabling high density, a wide memory window, and strong reliability for scalable FeRAM integration. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15081 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15081v1 Announce Type: new Abstract: Since its discovery, ferroelectric hafnia has been extensively studied due to its CMOS-compatibility and ability to remain polarized at sub-10 nm thicknesses. The ferroelectric behaviour is generally attributed to a polar orthorhombic (OIII) phase. However, a second polar phase with rhombohedral symmetry (R-phase) has also been reported in epitaxial films. The nature of the R-phase remains disputed due to the subtle differences with the OIII-phase when probed by standard thin film characterisation techniques. Given the functional properties of ferroelectrics are crucially determined by the crystal symmetry, resolving this matter is imperative. In this work, we settle the controversy through extensive 3D reciprocal space surveys made possible via synchrotron-based grazing incidence diffraction from epitaxial films of both phases. These experiments, together with direct comparison of their temperature dependence and electrical responses, conclusively establish them as two distinct phases and provide insight into their key characteristics. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14976 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14976v1 Announce Type: new Abstract: Non-van der Waals two-dimensional (2D) materials derived from strongly bonded non-layered crystals have recently emerged as a novel and rising platform for nanoscale research. While uncovering and tuning their (opto-)electronic, catalytic, and magnetic properties has been the focus of intense research, the impact of spin-orbit coupling (SOC) onto their electronic structure has not yet been explored in detail. Studying these effects is, however, particularly relevant due to their surface cation termination and the presence of heavy elements in several representative compounds. Here, we investigate the effect of SOC onto the electronic structure of 2D AgBiO3, NaBiO3, and SbTlO3. While the first two systems show negligible band renormalization upon inclusion of relativistic effects around the band gap, SbTlO3 showcases a large SOC induced splitting (229meV) for the lowest conduction bands associated with a band inversion. Substitution of Tl with Pb forming SbPbO3 brings the band-inverted feature to the Fermi level. Analysis of topological invariants and investigation of edge states of zig-zag and armchair ribbons within the 200meV gap confirms the topological nature of the band splitting. Our work thus establishes a foundation for the systematic study of robust non-van der Waals 2D topological insulators. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14947 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14947v1 Announce Type: new Abstract: Altermagnets are a new class of magnets accompanying global time-reversal symmetry breaking (TRSB) without net magnetization. The TRSB results in formation of novel altermagnetic domains. Features of altermagnetic domains, in particular their responses to external stimuli, are essentially important but yet unexplored. Here, we report visualization of bulk altermagnetic domains in MnTe based on scanning magneto-optical Kerr-effect microscopy using telecom infrared wavelength. We found two distinct TRSB domains with large Kerr rotations that do not scale with its tiny bulk magnetization. We also revealed controllability and stability of domains against magnetic or thermal perturbations. Our first observation of altermagnetic domains using a laboratory-scale simple optical technique showing their movable nature provide firm bases for future fundamental and application studies of altermagnets. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14894 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14894v1 Announce Type: new Abstract: We investigate optically induced phase transitions in the two-dimensional (2D) ferroelectric (FE) material Nb2O2I4 using real-time time-dependent density functional theory (rt-TDDFT). Our results demonstrate that tailored laser pulses can activate specific coherent phonon modes. Specifically, the anharmonic atomic distortions of the A1-1 and A1-2 modes at the {\Gamma}-point facilitate the reversal of in-plane polarization. By fine-tuning laser parameters, additional phonon modes at both the Y and {\Gamma} points are excited. The resulting nonequilibrium atomic dynamics enable the formation of previously unreported ferroic phases, including three antiferroelectric (AFE) phases and one ferrielectric (FiE) phase. Notably, these optically induced phases can be reverted to the initial FE state using appropriate techniques. This controllable reversibility among multiple ferroic phases positions 2D Nb2O2I4 as a highly promising candidate for next-generation electronic storage applications. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14845 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14845v1 Announce Type: new Abstract: Magnetoacoustic devices that harness the strong coupling between acoustic waves and magnons have emerged as a promising platform for energy-efficient spintronics. Laser-generated pulsed surface acoustic waves (SAWs) are particularly attractive for such applications, offering broadband frequency content up to the gigahertz (GHz) range, remote excitation without lithographic patterning, and surface localization for efficient on-chip integration. In this work, we present a comprehensive experimental study of laser-generated SAW pulses in the Fe49Rh51/MgO(001) system. A thin film of the near-equiatomic FeRh alloy serves both as an opto-acoustic transducer and as a mechanical load that modulates SAW propagation. The antiferromagnetic to ferromagnetic phase transition in FeRh, occurring slightly above room temperature, is accompanied by abrupt changes in its elastic properties, enabling controlled modification of the SAW excitation efficiency and dispersion characteristics by tuning the sample temperature and laser fluence. Using 160 fs laser pulses for excitation and time-resolved Sagnac interferometry for detection, we evaluated key SAW parameters, including amplitude, spectral content, phase and group velocities, and their in-plane anisotropy. Particular emphasis is placed on the dispersion relation and its anisotropy, which govern the coherent interaction between phonons and magnons and are determined primarily by the FeRh film. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14831 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14831v1 Announce Type: new Abstract: In this systematic density functional theory study, we compare a standard gradient corrected functional (PBE) with a long-range hybrid functional (HSE06), with and without correction for the dispersion forces, relatively to their ability to correctly reproduce structural and electronic properties of different bulk 3D C3N4 phases, encompassing diamond- and graphitic-like models. Corrugation is found to provide further stabilization to the layered structures with all methods. We observe that HSE06-D3 method provides results in good agreement with experimental data and with more sophisticated G0W0 calculations. Based on that, we exploited the method to investigate the nature of the bulk triplet excitons in these C3N4 structures to evaluate the S0-T1 energy difference, the selftrapping triplet exciton energy and the photoluminescence emission energy, since this is a promising vis-light photocatalyst. Nanostructuring (0D and 2D) is another relevant aspect of these materials in practical applications, therefore we have considered the effect of single or multilayer exfoliation or space confinement in nanoparticles. Finally, we also discuss how the introduction of extrinsic dopants (e.g. S atoms) in the nanostructures modifies the atomic and electronic structure. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14821 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14821v1 Announce Type: new Abstract: We present a study of the melting dynamics of a two-phase eutectic solid. In situ, thin-sample experiments using a transparent eutectic alloy and two-dimensional phase field simulations calibrated for the very same alloy are combined to assess pattern formation during directional melting in a temperature gradient. Depending on the melting velocity $V_m$ and the spacing $\lambda$ of the pre-solidified lamellar microstructure, an unexpectedly rich diversity of melting patterns is observed, with good agreement between experiments and simulations. We unravel the different physical mechanisms leading to this diversity, and establish the scaling behaviors of (i) the penetration of the liquid along the solid-solid interface at large $V_m$, (ii) the thickening of the primary-phase fingers at low $V_m$, and (iii) a period-doubling instability for small $\lambda$ values. Our study provides a fundamental basis for further investigations of eutectic melting, including additive manufacturing during which melting/solidification cycles take place. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14776 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14776v1 Announce Type: new Abstract: Altermagnet-based heterojunctions have demonstrated magnetoresistive effects in experiments, however, a predictive theoretical model for non-ferromagnetic structures has remained elusive. In this work, we develop a tunneling-based spin-transport theory that explicitly incorporates the transverse-wavevector ($\bf{k}_\|$)-dependent spin polarization of an altermagnet's transport channels, enabling the prediction of giant tunneling magnetoresistance (TMR). Based on the theory, we predict that the altermagnet KV$_2$Se$_2$O can reach the extreme limit of magnetoresistance. By performing first-principles transport calculations, we verify that magnetic tunnel junctions using the metallic KV$_2$Se$_2$O as the electrodes and few-layer MgO as the spacer exhibit zero-bias magnetoresistance larger than $7.57\times10^7$\%, which is robust against the bias and thickness of the spacer. Our research provides a quantitative design principle for next-generation spin-electronic devices and establishes KV$_2$Se$_2$O/MgO/KV$_2$Se$_2$O as a leading candidate material system for room-temperature ultra-high-density non-volatile memory. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14764 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14764v1 Announce Type: new Abstract: Rutile RuO$_2$ has attracted great interest recently, as its magnetic ground state remains controversial. Experimental studies have reported either nonmagnetic or altermagnetic (AM) ground states in different crystalline samples of RuO$_2$, highlighting the need for a reasonable explanation to resolve this contradiction. In this study, density functional theory calculations are performed to reveal the correlation-sensitive and strain-dependent magnetism of bulk RuO$_2$. On one hand, multiple AM phases with different magnitudes of the spin magnetic moment are identified in the Hubbard parameter space for RuO$_2$. On the other hand, when appropriate strains which significantly change the crystal cell volume are applied, the ground state of RuO$_2$ can undergo transitions between the nonmagnetic state with no spin splitting and the magnetic states with spin splitting in the band structure. These findings not only demonstrate intriguing physics in 4d-electron-correlated RuO$_2$, but also retain its potential for spintronic applications. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14750 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14750v1 Announce Type: new Abstract: Mound formation on flat and miscut crystal surfaces exhibits distinct growth behaviors. While mound structures are the predominant feature on flat surfaces, miscut surfaces display a smooth transition from meandered patterns to three-dimensional mounds, depending on both internal and external conditions. We investigate this morphological evolution-from meander-like surface patterns to faceted pyramidal structures-using a vicinal Cellular Automata modeling framework. The transition is shown to be governed by the competition between the Ehrlich-Schwoebel barrier and adatom mobility on terraces. Under moderate barrier strengths and sufficiently high terrace diffusivity, the system demonstrates a reversible transition from mounded configurations to regular step meandered patterns. This reveals a complex interplay between kinetic barriers and mass transport. Our simulations cover a wide range of growth conditions, including variations in deposition flux, surface diffusion rates, temperature, and miscut angle. By applying the height-height correlation function, we calculate the correlation lengths along and across the steps and analyze their scaling behavior. These results offer insight into the continuum pathways that connect distinct classes of surface structures and provide a unified framework for describing pattern evolution across different crystal growth regimes. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14680 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14680v1 Announce Type: new Abstract: Electroforming of metal-oxide-metal memristors is generally attributed to the creation of oxygen-vacancy filaments within the oxide, with noble metal electrodes such as Pt and Au remaining chemically inert. Here, we demonstrate that electroforming and subsequent operation of Pt/NbOx/Nb2O5/Pt devices can induce an unexpected and highly correlated redistribution of both oxygen and platinum. Time-of-flight secondary ion mass spectrometry reveals a filamentary pathway characterized by micrometer-scale oxygen enrichment extending from the Nb2O5 layer through NbOx and deep into the Pt top electrode. Surprisingly, this is accompanied by the formation of a Pt-rich filament penetrating the oxide stack along the same filamentary path. Finite-element and lumped-element modelling show that current-controlled negative-differential-resistance operation produces localized Joule heating and high-frequency thermal cycling, which strongly enhances oxygen migration and enables thermally assisted Pt diffusion along vacancy-rich pathways. These findings reveal a previously unrecognized metal-ion transport mechanism in NbOx memristors and highlight the critical role of post-forming electrical dynamics in determining filament chemistry, stability, and device reliability. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14554 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14554v1 Announce Type: new Abstract: Mg-IV-N\textsubscript{2} compounds with IV=Si, Ge, Sn are ultra-wide band gap semiconductors with various potential electronic and optoelectronic applications. They share the \textit{Pna}2\textsubscript{1} space group crystal structure. Here we present Density Function Perturbation Theory (DFPT) calculations of the vibrational modes of these materials. We focus on the vibrational modes at the zone center to establish the relation between vibrational modes and their corresponding point-group symmetries, which determine the Raman and infrared spectra but also report the full Brillouin zone phonon dispersions and density of states. We also determine the piezoelectric tensor and the elastic compliance tensor. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14509 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14509v1 Announce Type: new Abstract: As the number of theoretically predicted materials continues to grow, it becomes increasingly important to assess not only their thermodynamic stability but also their kinetic viability under realistic synthesis conditions. In this study, we investigate the hypothesis that the kinetic persistence of a metastable polymorph is related to the topography of the potential energy landscape separating it from lower energy phases. To accomplish this, we develop a new method for identifying diffusionless transformation pathways between metastable polymorphs and their ground-state counterparts and discuss the energetics of those pathways with respect to the experimental observation of each phase. This algorithm is underpinned by the recently developed Crystal Normal Form, which provides a graph representation of crystal configuration space and supplies the substrate for our pathfinding algorithm. We apply this method to the titanium dioxide system which contains the well-known anatase, rutile, and brookite phases in addition to a number of hypothetical metastable polymorphs. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14470 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14470v1 Announce Type: new Abstract: \textit{Ab initio} pseudo-atomic orbital (PAO) Hamiltonians express the electronic structure of a solid in a compact, localized basis that spans the same Hilbert space as a conventional Slater--Koster tight-binding model, thereby providing an exact \textit{ab initio} representation without any loss of accuracy. Building on this correspondence, we develop an environment-dependent tight-binding (EDTB) framework in which Slater--Koster hopping integrals are augmented with bond-screening functions that capture the local coordination environment. All parameters are determined by fitting to the PAO eigenvalue spectrum across multiple atomic configurations simultaneously, which breaks the degeneracy between screening and hopping parameters and yields physically meaningful, transferable models capable of generating Hamiltonians for large systems with \textit{ab initio} precision. We demonstrate the efficiency and accuracy of the approach on four prototypical systems: bulk platinum, silicon surfaces, Si/Ge~[001] superlattices, and twisted bilayer graphene with up to $4{,}324$ atoms. The method is implemented in the \paoflow{} code and integrates seamlessly with its full post-processing suite, enabling the evaluation of a broad range of electronic, optical, and transport properties. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14443 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14443v1 Announce Type: new Abstract: The large-area synthesis of high-crystalline-quality two-dimensional (2D) materials is at the core of novel material integration for semiconductor technology. This effort relies on developing fabrication and characterization techniques that can uncover the material's intrinsic properties by preserving its pristine conditions. In this article, we present an all ultra-high-vacuum cluster for the growth using molecular beam epitaxy of 2D semiconductors that are unstable under ambient conditions and optical spectroscopy using low temperature (20 K) photoluminescence and Raman scattering. The optical chamber of the setup provides micrometer scale spatial resolution and the ability to scan the entire wafer. The performance of its setup regarding spatial resolution, temperature control over a temperature range of 20-300 K using a closed-cycle cryostat and long-term preservation are demonstrated using as-grown post-transition metal monochalcogenides. Furthermore, we introduce a deconvolution-based algorithm to recover spatial information under vibration using a system-specific point-spread function. This enables in situ analysis of the structural and optoelectronic properties of as-grown materials in their pristine form, providing rich and reproducible feedback for both fundamental studies and the optimization of scalable 2D material growth toward integration in advanced devices. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2404.14932 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2404.14932v4 Announce Type: replace Abstract: We investigate the structural and electronic reconstruction associated with the commensurate charge-density-wave (CCDW) phase in bulk and monolayer 1T-TaS2 using density functional theory (DFT) and Wannier-based tight-binding modeling. Structural relaxation of a sqrt(13) x sqrt(13) supercell leads spontaneously to the formation of the Star-of-David (SoD) distortion, consistent with phonon softening of the undistorted phase. We focus on establishing a direct connection between real-space lattice distortion and momentum-space electronic reconstruction. Using Wannier interpolation, we demonstrate how the CCDW-induced Brillouin zone reduction leads to band folding, narrowing of Ta 5d bands, and reconstruction of the Fermi surface. Our analysis shows that features often interpreted as Fermi surface nesting emerge naturally from band folding associated with lattice distortion. We compare our calculated electronic structure with previously reported angle-resolved photoemission spectroscopy (ARPES) results at a qualitative level. While we do not explicitly compute electronic susceptibility or electron-phonon coupling matrix elements, the results provide a consistent microscopic framework linking lattice instability and electronic structure reconstruction in 1T-TaS2. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15213 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15213v1 Announce Type: cross Abstract: We explore the expected performance of a semiconducting spin cQED quantum processor for Multiple Hypothesis Tracking (MHT) algorithm via a quantum annealing procedure. From two different benchmarking scenarios we evaluate this type of quantum annealer on a quantum emulator in which we incorporated both dynamical coherent errors and incoherent errors. From estimate of the reset, measurement and annealing time of the processor, we find that cQED-spin processors could reach a total run time of around 50 ms. This makes this technology promising for potential real time application such as radar tracking. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15091 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15091v1 Announce Type: cross Abstract: Collective spin systems -- spin ensembles coupled to a common reservoir and effectively described by a single macrospin -- play an important role in both atomic and solid-state physics. Their intrinsic nonlinearity gives rise to multiple long-lived metastable states that ultimately relax to a unique most probable state. This dominant state can change with a control parameter, leading to first-order phase transitions. We develop a real-time instanton approach based on quantum quasiprobability dynamics that captures the stationary state in the large-spin limit and the asymptotic scaling of relaxation rates. We further show that these features are not accurately described by the previously applied semiclassical Wigner approach due to its neglect of non-Gaussian fluctuations. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15019 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15019v1 Announce Type: cross Abstract: Magnetic skyrmions are emerging as promising candidates for next-generation information technologies, while the realization of scalable skyrmion lattices with tailored configurations is essential for advancing fundamental skyrmion physics and developing future applications. Here we achieved the controllable generation and regulation of a large-area, highly oriented skyrmion track array (STA) in ferromagnetic Fe3GaTe2 using a vector magnetic field manipulation technique. The orientation and ordering of STA, along with the types and density of skyrmions, are precisely controlled by modulating parameters during the manipulation. The critical roles of in-plane magnetic fields and Dzyaloshinskii-Moriya interaction in STA generation is further confirmed by micromagnetic simulation. Our findings develop a strategy for engineering large-area and highly-oriented skyrmion configurations, offering a new pathway for the future application of next-generation spintronic and information technologies. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14917 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14917v1 Announce Type: cross Abstract: Active colloidal microparticles require reliable actuation to sustain directed motion. Light-based propulsion is particularly attractive as it provides persistent energy supply and enables direct spatiotemporal control. Here, we introduce 3D-printable particles with symmetry-broken refractive index profiles (SBRIP particles) that achieve propulsion through direct momentum transfer from asymmetric light refraction. Internal refractive-index gradients provide optical symmetry breaking independent of external shape, fundamentally decoupling propulsion from particle geometry. Geometrically symmetry-broken particles with a homogeneous refractive index are another special case, where propulsion originates from refractive contrast at the boundary instead of within the particle. Unlike conventional systems relying on absorption or reflection, this transparency-based mechanism minimizes heating and mitigates shadowing in bulk suspensions. We present a theoretical framework for refractive propulsion as well as numerical simulations of the SBRIP particles using raytracing and the finite volume method. This is complemented by experiments, validating the momentum transfer mechanism using particles with geometric symmetry breaking. The high transparency of our particles ensures deep light penetration, enabling the realization of volumetric active matter. This opens pathways toward adaptive nonlinear optical materials where light-driven particle reorganization modulates the local refractive index, establishing a dynamic feedback loop between the optical field and the material structure. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14538 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14538v1 Announce Type: cross Abstract: The spontaneous breaking of symmetries is a cornerstone of physics, defining the phases of matter from the cosmological scale to the quantum realm. In condensed matter, electronic orders are classified by their behavior under fundamental symmetries like spatial inversion (parity). While even-parity orders, such as conventional superconductivity and charge density waves, are ubiquitous, their odd-parity counterparts--predicted to host exotic phenomena such as gapless quasiparticle excitations and novel collective modes--are comparatively elusive states of quantum matter. Here, using high-resolution scanning tunneling microscopy and angle-resolved photoemission spectroscopy on the kagome metal CsV$_3$Sb$_5$, we report the discovery of an inversion symmetry-breaking $f$-wave charge bond order. We show that this phase, which preserves translation symmetry, is stabilized by the spontaneous opening of a spectral gap at a previously overlooked Dirac point, providing a textbook condensed-matter realization of the Gross-Neveu model for dynamical mass generation and parity breaking. Intriguingly, this $f$-wave order is itself a intervening phase, vanishing abruptly below a temperature of 10\,K and pointing to a subsequent transition into a `hidden' electronic state that is invisible to local STM probes. Our findings establish odd-parity charge order as a novel phase of matter, here, embedded within the intricate hierarchy of correlated electronic orders on the kagome lattice. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14533 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14533v1 Announce Type: cross Abstract: The single orbital, one-dimensional, Hatano-Nelson Hamiltonian provides deep insight into the physics of non-Hermiticity, resulting from asymmetric left/right hopping, and its connections to localization. In the absence of disorder, its single particle eigenvalues $E_{\alpha}$ lie on an ellipse in the complex plane whose extent in the imaginary direction is controlled by the degree of asymmetry. When randomness is introduced, two sets of real eigenvalues emerge at the extremes of the largest and smallest real part of $E_{\alpha}$. These real eigenvalues are associated with localized eigenvectors. For spinless fermions, increasing near-neighbor interactions first cause a transition to a charge density wave phase, and ultimately, on finite lattices, a collapse of all eigenvalues to the real axis. In this paper, we explore the presence of real eigenvalues in the interacting, two-particle sector for the spinful case (Hubbard model) in a two-chain (two-band) geometry with a Hermitian interchain hopping. Our key results are to obtain the ``phase" diagrams for the existence of a purely real spectrum, as a function of the interaction strength, degree of non-Hermiticity, and interchain hopping. We study the sensitivity to boundary conditions of the spectral properties of our two-chain model with winding number analysis and explore the relationship between PBC doublon states and OBC skin modes. To address the question of stability in such non-equilibrium systems, we solve the dynamics at low filling according to Lindbladian evolution and find that the non-Hermitian description is able to qualitatively describe such systems. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14382 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14382v1 Announce Type: cross Abstract: The Lindblad (GKLS) master equation, which represents the mathematical form for the general evolution of a density matrix, is a versatile and widely-used tool in open quantum systems. In contrast with the typical approach of imposing additional conditions on the system, such as weak coupling or energy conservation, we explore the structure of the equation with no assumptions. We demonstrate that general quantum dynamics can be expressed through a combination of free evolution, exchanges of some physical quantities (generalised charges), not necessarily commuting with the Hamiltonian, between the system and the bath, and pure dephasing. This result comprises a novel perspective on quantum master equations, employing physical processes as elemental parts. We use it to explore the dynamics and stationary states of a two-level system and show that strong coupling, particle exchange, and non-Abelian effects all share the same physical origin. Moreover, we demonstrate that the generalised Gibbs state for all three cases contains a non-commutation term, which has not been previously considered. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14378 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14378v1 Announce Type: cross Abstract: The Klein Paradox -- the anomalous scattering of relativistic fermions off a high potential step -- signals the limit of the single-particle interpretation of the Dirac equation. While Quantum Field Theory (QFT) resolves this via pair production, the microscopic mechanism is often obscured by abstract formalism. In this work, we investigate this phenomenon through the framework of Analog Gravity and Condensed Matter Physics. We utilize a hydrodynamic model wherein a relativistic particle is treated as a localized elastic excitation (defect) within a continuous linear medium. We demonstrate that when the external stress (potential) exceeds the medium's binding energy threshold ($V > 2mc^2$), the system undergoes a mechanical instability analogous to dielectric breakdown. This instability naturally generates modes with inverted topological winding, which we identify as antiparticles. By solving the boundary conditions for this elastic system, we reproduce the transmission coefficients of Hansen and Ravndal and recover the Schwinger limit for pair production rates. This approach provides a clear pedagogical model based on continuum mechanics to visualize vacuum decay processes, suggesting that the "paradox" is simply the elastic response of a medium under supercritical stress. This mechanical analogy serves as a pedagogical bridge for graduate students in condensed matter physics and advanced materials science, offering a concrete visualization of vacuum instability that complements standard abstract QFT derivations. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15276 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15276v1 Announce Type: new Abstract: Over the last decade, the development of Josephson devices based on van der Waals (vdW) materials has advanced rapidly, representing a paradigm shift driven by the advent of 2D materials. The diverse vdW materials library, combined with advanced fabrication techniques, enables the integration of materials with vastly disparate properties for scientific exploration. The vdW Josephson junctions (JJs) offer a unique route to explore novel functionalities and associated physics that remain inaccessible in conventional JJs, which have reached an industrial level in terms of fabrication. Beyond material diversity, vdW crystalline materials offer fundamental new control over device symmetries, enabling the realization of Hamiltonians unique to 2D systems. Furthermore, the long relaxation times of myriad excitations in 2D heterostructures open possibilities for creating exquisite quantum sensors, with the 2D material itself acting as an efficient bus for transmitting excitations to the active sensing element. This creative explosion in vdW-based superconducting electronics is rapidly growing, and our review highlights the resulting devices and physics. The confluence of vdW JJs with twistronics and topology has the potential to redefine superconducting quantum technology, enabling applications from quantum computation to ultra-sensitive hybrid sensors. While opportunities abound with vdW JJs, the challenge of scalability must be surmounted for translation into real-world devices. This review synthesizes current developments and offers a roadmap for researchers navigating this burgeoning field. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15133 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15133v1 Announce Type: new Abstract: We propose a Hanbury Brown-Twiss interferometer for a $\nu=2/5$ fractional quantum Hall edge system, in which quasiparticles tunnel between two co-propagating edge modes. In contrast to the previously studied anyonic Fabry-P\'{e}rot and Mach-Zehnder interferometers, the proposed setup relies purely on two-particle interference rather than single-particle interference. In the weak-tunneling regime, we employ a bosonized edge theory together with Keldysh perturbation theory to evaluate the cross-correlation of the tunneling currents. In the large-device limit, we obtain an analytic expression for the flux-dependent noise, whose structure closely resembles that of an electronic HBT interferometer, but with the electron charge replaced by the fractional charge $e^{\star}=e/3$ and with scaling dimensions characteristic of the fractional edge modes. In this limit, the explicit anyonic exchange phases cancel, whereas when the device size becomes comparable to the thermal length, the cross-correlation may recover a more explicit dependence on the anyonic statistical angle. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15062 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15062v1 Announce Type: new Abstract: Hydrodynamic electron transport, namely, the electric behaviors in solid materials at the macroscopic level are similar to the fluid hydrodynamics when the momentum-conserving electron-electron scattering plays the leading role, has got much attention in the past ten years. However, most of previous studies mainly focus on the electric properties. In this work, the thermal behaviors of hydrodynamic electron transport in a homogeneous 2D Corbino disk geometry is studied by the electron Boltzmann transport equation (eBTE) coupled with the Poisson equation under the magnetic field perpendicular to disk plane. Results show that in the electron hydrodynamic regime, the heat flux deflection phenomenon appears under the radial electric field or temperature gradient, namely, the heat flux no longer flows only along the radial direction and there is heat flux in the tangential direction of the radius. Heat flux deflection phenomenon is suppressed by momentum-relaxing scattering process and promoted by momentum-conserving scattering process. When an electric potential gradient or temperature gradient in the same direction is applied separately, the direction of heat flux is reversed in the electron hydrodynamic regime. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15036 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15036v1 Announce Type: new Abstract: Quantum dot based platforms offer a promising route towards realizing the Kitaev chain Hamiltonian hosting Majorana bound states (MBSs). Poor man's MBSs arise in a two-site Kitaev chain when the parameters of the system are fine-tuned to the sweet spot. Based on our previous work [Phys. Rev. B 111, 155410 (2025)], we consider a microscopic model for the Kitaev chain based on quantum dots with proximity effect embedded in a photonic cavity. We find that the photon coupling in the microscopic model yields an effective Hamiltonian where the cavity affects the pairing term. However, we demonstrate that even in this case, it is possible to screen particle interactions and reach the sweet spot condition for the emergence of the poor man's MBSs. In particular, we find that attractive particle interactions can be canceled for the cavity prepared in the zero-photon state, while repulsive ones can be screened with a cavity prepared in the one-photon state. Furthermore, in case of a large number of photons in the cavity, we find that the hopping amplitudes are suppressed resulting in a degenerate spectrum. This motivates the use of quantum light for engineering poor man's MBSs with cavity embedding. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14817 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14817v1 Announce Type: new Abstract: Magnetic tunnel junction (MTJ) is the key component to enable information access and increasing number of MTJs is integrated to develop high-density spintronic devices. However, continuous miniaturization of the conventional MTJs is hindered by stray magnetic fields. Altermagnets, combining the advantages of both ferromagnets and antiferromagnets, provide a promising alternative to fabricate versatile MTJs with exotic properties, such as giant spin splitting, high intrinsic frequency, and absence of stray fields. Inspired by the altermagnetic metal candidate KV2Se2O reported recently, we design an altermagnetic tunnel junction (AMTJ) based on KV2Se2O/SrTiO3/KV2Se2O. Using density functional theory combined with non-equilibrium Green's function, we investigate the layer-dependent quantum transport properties and the tunneling magnetoresistance (TMR) of such AMTJ device. Our calculated results reveal that the transmission of the AMTJ device exhibits a pronounced oscillation behavior dependent on the number of layers of the SrTiO3 semiconductor, which is attributed to the interface configuration determined by parity of the layer number. In odd-layer devices, the electron-rich O-Se interface exhibits a smooth effective potential and enables transverse momentum (k||) transport channels, leading to enhanced transmission. In contrast, in even-layer devices, the Ti-Se interface presents a steeper effective potential, impeding quantum transport through transverse momentum (k||) channels. A giant TMR of 4.6*10^7% is predicted to be realized by using a 4-layer SrTiO3. Our findings not only provide physical understanding relevant to the quantum transport in AMTJs, but also unveil that the barrier interface engineering is a strategy to tune the magnetoelectric performance. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14780 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14780v1 Announce Type: new Abstract: While significant advancements have been made in weak magnetic field detection, conventional high-sensitivity techniques are often limited by requirements for cryogenic operation or bulky setups. In this work, we develop a sensitive alternating magnetic field sensor based on a coupled system of an active microwave cavity and yttrium iron garnet (YIG), with the components implemented on printed circuit boards (PCBs). By introducing electrically tunable gain to compensate for cavity losses, we substantially improve both the quality factor and the signal intensity. Under the coupled system, Floquet modulation is induced by the alternating magnetic field, allowing for weak field detection by driving a specific hybrid mode and measuring the resulting Floquet sidebands. This miniaturized device operates at room temperature, achieving a detection limit of 121 pT/\sqrt{Hz}. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14777 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14777v1 Announce Type: new Abstract: Nanofluidic devices prompts unconventional ion transports appealing to energy and information technologies, thanks to the susceptibility of confined electric double layers (EDL) to various external physical fields. Although experimental studies advance rapidly, the rationalization of field-tunable nanofluidic transports has not reached a formalized and unified level. Here we formally reformulate the Poisson-Boltzmann theory and reveal distinct EDL regimes on the parameter space. Based on the regime classification, we establish a formal framework for the tunable nanofluidic transport, which reproduces the observed conductivity-concentration scaling behaviors, rationalizes the ionic transistors with reconfigurable polarities, and predicts two fundamental thermodynamic limits for electrostatic modulation (60 mV/dec and 120 mV/dec). Being accurate, generalizable and extensible, this framework can account for a wide range of ion transports in confined spaces. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14770 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14770v1 Announce Type: new Abstract: Phononic silicon structures have emerged as an integrable and scalable nanosystem for tailoring thermal transport. However, their widespread adoption has been limited by their complex fabrication pathways. Alongside, the reliable characterization of thermal properties in suspended nanostructured films remains challenging, as thermal contact resistances often hinder the accuracy of measurements. In this work, we demonstrate a clear and controllable reduction of thermal conductivity in nanopatterned silicon membranes. A block copolymer self-assembly approach is employed to fabricate nanoholed silicon films with a pitch of 63 nm and hole diameters of 35 nm. Additionally, we introduce an extension of the three-probe technique that enables robust, quantitative, and spatially resolved thermal conductivity measurements in complex thin-film systems, accounting for thermal contact artifacts. The method is validated through measurements on unpatterned 40 nm-thick silicon thin films between 30 and 350 K, yielding a room-temperature thermal conductivity of 46.5 W/m.K. Finally, we further show that controlled etching of the nanoholes provides a powerful means to tune thermal transport in the overall studied temperature range, establishing hole etch depth control as an effective parameter in phononic silicon. Specifically, a fivefold reduction in thermal conductivity is achieved, reaching 7.3 W/m.K for fully etched-through membranes at room temperature. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14737 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14737v1 Announce Type: new Abstract: Advances in nanotechnology now allow the creation of artificial atoms - engineered structures whose electronic states closely mimic those of real atoms. Understanding how these artificial atoms interact and bond is key to designing new materials with tailored electronic properties. Here, we use scanning tunnelling microscopy to visualise the bound states of nanostructures patterned in a two-dimensional molecular film featuring a parabolic band with multiple partial energy gaps. The lowest-energy states split off from the bottom of the band and resemble the familiar $s$ and $p$ orbitals of natural atoms, even bonding in the same way. Yet, artificial atoms go beyond this analogy: the gapped two-dimensional vacuum in which they reside gives rise to entirely new orbitals with no counterparts in real atoms. These quasi-one-dimensional localised states enrich the orbital vocabulary of chemistry, adding a new class of orbitals that are predominantly shaped by the surrounding electronic vacuum. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14665 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14665v1 Announce Type: new Abstract: Utilization of Faraday rotation (FR) properties of topological materials offers a promising route toward novel magneto-optical devices. We systematically investigated the effect of Rashba spin-orbit coupling (SOC) on FR spectra in an extended Haldane model, which incorporates Rashba SOC and exchange splitting into the original spinless Haldane framework. Using the Kubo formalism, we calculated the FR spectra across the model's rich topological phase diagram. We found that in the Chern number C=2 region, in the absence of exchange splitting, the FR angle can exceed 4$^\circ$ and its peak position is tunable by the Rashba SOC. In contrast, with the inclusion of exchange splitting, a nearly flat FR profile emerges over a broad frequency range, and the FR peak values increase monotonically with the Rashba SOC strength. The Rashba SOC opens additional transition channels, whose net contribution constructively enhances the FR peak. Furthermore, we derived a low-energy effective Hamiltonian expanded up to quadratic terms, the results of which are in good agreement with tight-binding model calculations, thereby validating our numerical results. Our findings suggest that magneto-optical device characteristics can be designed and optimized through Rashba SOC engineering. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14521 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14521v1 Announce Type: new Abstract: We theoretically study the direct and inverse spin Hall effects in a superconductor-normal metal-superconductor junction induced by a spin-orbit interaction that is invariant under spatial inversion. We show that a supercurrent induces a spin Hall effect, leading to a static spin accumulation with opposite polarizations at the two edges, analogous to that in normal conductors. For the inverse effect, we consider a spatially inhomogeneous static magnetic field and show that it induces an anomalous phase shift, which, in the presence of higher harmonics, results in a diode effect. Unlike Rashba systems, the present mechanism does not require broken structural inversion symmetry. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2601.01309 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2601.01309v3 Announce Type: replace-cross Abstract: Disorder in quantum many-body systems can drive transitions between ergodic and non-ergodic phases, yet the nature--and even the existence--of these transitions remains intensely debated. Using a two-dimensional array of superconducting qubits, we study an interacting spin model at finite temperature in a disordered landscape, tracking dynamics both in real space and in Hilbert space. Over a broad disorder range, we observe an intermediate non-ergodic regime with glass-like characteristics: physical observables become broadly distributed and some, but not all, degrees of freedom are effectively frozen. The Hilbert-space return probability shows slow power-law decay, consistent with finite-temperature quantum glassiness. In the same regime, we detect the onset of a finite Edwards-Anderson order parameter and the disappearance of spin diffusion. By contrast, at lower disorder, spin transport persists with a nonzero diffusion coefficient. Our results show that there is a transition out of the ergodic phase in two-dimensional systems. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2507.08930 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2507.08930v2 Announce Type: replace-cross Abstract: We present a formalism that allows for the direct manipulation and optimization of subspaces, circumventing the need to optimize individual states when using subspace methods. Using the determinant state mapping, we can naturally extend notions such as distance and energy to subspaces, as well as Monte Carlo estimators, recovering the excited states estimation method proposed by Pfau et al. As a practical application, we then introduce Bridge, a method that improves the performance of variational dynamics by extracting linear combinations of variational time-evolved states. We find that Bridge is both computationally inexpensive and capable of significantly mitigating the errors that arise from discretizing the dynamics, and can thus be systematically used as a post-processing tool for variational dynamics. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2510.24704 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.24704v2 Announce Type: replace Abstract: We investigate long-range resonances in quasiperiodic many-body localized (MBL) systems. Focusing on the Heisenberg chain in a deterministic Aubry-Andr\'{e} potential, we complement standard diagnostics by analyzing the structure of long-distance pairwise correlations at high energy. Contrary to the expectation that the ergodic-MBL transition in quasiperiodic systems should be sharper due to the absence of Griffiths regions, we uncover a broad unconventional regime at strong quasiperiodic potential, characterized by fat-tailed distributions of longitudinal correlations at long distance. This reveals the presence of atypical eigenstates with strong long-range correlations in a regime where standard diagnostics indicate stable MBL. We further identify these anomalous eigenstates as quasi-degenerate pairs of resonant cat states, which exhibit entanglement at long distance. These findings advance the understanding of quasiperiodic MBL and identify density-correlation measurements in ultracold atomic systems as a probe of long-range resonances. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2505.20954 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2505.20954v4 Announce Type: replace Abstract: We define and study a statistical mechanics ensemble that characterizes connected solutions in constraint satisfaction problems (CSPs). Built around a well-known local entropy bias, it allows us to better identify hardness transitions in problems where the energy landscape is dominated by isolated solutions. We apply this new device to the symmetric binary perceptron model (SBP), and study how its manifold of connected solutions behaves. We choose this particular problem because, while its typical solutions are isolated, it can be solved using local algorithms for a certain range of constraint density $\alpha$ and threshold $\kappa$. With this new ensemble, we unveil the presence of a cluster composed of delocalized connected solutions. In particular, we demonstrate its stability until a critical threshold $\kappa^{\rm no-mem}_{\rm loc.\, stab.}$ (dependent on $\alpha$). This transition appears as paths of solutions shatter, a phenomenon that more conventional statistical mechanics approaches fail to grasp. Finally, we compared our predictions to simulations. For this, we used a modified Monte-Carlo algorithm, designed specifically to target these delocalized solutions. We obtained, as predicted, that the algorithm finds solutions until $\kappa\approx\kappa^{\rm no-mem}_{\rm loc.\, stab.}$. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2502.10918 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2502.10918v3 Announce Type: replace Abstract: Glasses are traditionally characterized by their rugged landscape of disordered low-energy states and their slow relaxation towards thermodynamic equilibrium. Far from equilibrium, dynamical forms of glassy behavior with anomalous algebraic relaxation have also been noted, for example, in networks of coupled oscillators. Due to their disordered and high-dimensional nature, such systems have been difficult to study theoretically, but data-driven methods are emerging as a promising alternative that may aid in their analysis. Here, we characterize glassy dynamics using the dynamic mode decomposition, a data-driven spectral computation that approximates the Koopman spectrum. We show that the gap between oscillatory and decaying modes in the Koopman spectrum vanishes in systems exhibiting algebraic relaxation, and thus, we propose a model-agnostic signature for robustly detecting and analyzing glassy dynamics. We demonstrate the utility of our approach through both a minimal example of a one-dimensional ODE and a high-dimensional example of coupled oscillators. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.14718 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14718v1 Announce Type: cross Abstract: This article argues that the most important significance of the AI revolution, especially the rise of large language models, lies not simply in automation, but in a fundamental change in how complex information and human know-how are carried, replicated, and shared. From this perspective, AI for Science is especially important because it may transform not only the efficiency of research, but also the structure of scientific collaboration, discovery, publishing, and evaluation. The article outlines a gradual path from AI as a research tool to AI as a scientific collaborator, and discusses how AI is likely to fundamentally reshape scientific publication. It also argues that continuous learning and diversity of ideas are essential if AI is to play a meaningful role in original scientific discovery. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.14387 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14387v1 Announce Type: cross Abstract: Recent work has emphasized a subtlety of large- $N$ limits in AdS/CFT: a sequence of pure states in the microscopic theory need not remain pure with respect to the emergent algebra of observables. We study this phenomenon for Kourkoulou-Maldacena (KM) states in the double-scaling limit of the SYK model, and show that their ensemble-averaged algebraic description depends crucially on which observables survive the limit. For fermionic operators of size $N^{1/2}$, generic operators converge to the usual chord operators of double-scaled SYK. The resulting von Neumann algebra is the standard Type II$_1$ factor, and the KM pure states at infinite temperature converge to the tracial state, so generic probes lose access to microscopic purity. We then identify a class of operators adapted to the KM state that also survives the double-scaling limit. Since the KM state may be viewed as a projection inside the tracial state, these become dressed chord creation and annihilation operators. Once included, the limiting algebra becomes Type I$_\infty$ and the limiting state becomes pure. This gives a concrete example in which adding a sufficiently state-adapted operator to the emergent algebra restores access to the purity of the underlying state. We further show that correlators of the dressed operators admit exact modified chord-diagram rules, derive analytic expressions for uncrossed $2n$-point and crossed four-point functions, analyze their finite-temperature semiclassical and Schwarzian limits, study a deformation of the chord Hamiltonian that produces bound states and extends the correspondence with JT gravity plus an EOW brane to general brane tension, and identify an emergent $U(1)$ symmetry together with its finite-$N$ violation. Finally, we discuss analogies with boundary algebras proposed for black hole interiors and closed universes, and suggest lessons from our construction for both. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.14335 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14335v1 Announce Type: cross Abstract: We derive the reduced Dirac Hamiltonian on the non-rotating BTZ background and use its redshift structure to construct a gauge-covariant single-band lattice model on the constant-time BTZ cylinder. In equal-area coordinates the AdS radius $L$ fixes the local Gaussian curvature, while the horizon radius $r_h$ fixes the throat size and the strength of the near-horizon redshift. The lattice model therefore has a direct geometric interpretation and is not presented as an unshown reduction of the two-component Dirac lattice. Its angular Fourier transform yields an exact curved Harper equation with BTZ-dependent hopping amplitudes and a consistent dimensionless angular quasi-momentum. We then supplement global parameter scans with state-resolved diagnostics: spectra color-coded by mean radius, local density of states, direct flux-response versus radius correlations, and Aharonov--Bohm spectral flow and persistent current on the BTZ cycle. These results show that weaker curvature sharpens the butterfly-like fragmentation, whereas larger horizons suppress both magnetic and Aharonov--Bohm response by creating weakly dispersing near-horizon states. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2512.24501 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2512.24501v2 Announce Type: replace Abstract: A model of microscopic interaction between a superconductor and a one-dimensional topological insulator, an SSH chain, is considered. Using the functional integration method, the effective action of the interaction between a superconductor and a topological insulator is obtained. We obtain corrections to the quasiparticle excitation spectrum of the SSH chain due to tunneling in various limits and discuss the influence of phase fluctuations. We find that for bulk superconductors, the states of the chain are stable for energies lying inside the superconducting gap while in lower-dimensional superconductors phase fluctuations yield finite temperature-dependent lifetimes even inside the gap. We also discuss whether these results can be reproduced within a simple phenomenological approach. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2510.24404 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.24404v3 Announce Type: replace Abstract: An interaction between ferromagnetic and superconducting orders, to be realized in a two dimensional ferromagnetic superconductor, is proposed obeying necessary symmetry principles. This interaction allows us to formulate a duality, similar to the Boson-vortex duality in 2+1 dimensional superfluid. In the dual theory the Skyrmion and the vortex excitations interact with each other via an emergent gauge field. The static interaction potential is attractive for a Skyrmion and a vortex with opposite topological charges. This interaction can lead to formation of bound pairs of the mentioned topological excitations. Furthermore, we argue that such pairing implies that a Magnus force acting on the vortex induces a transverse, Hall-like drift motion of the Skyrmion, which we term the vortex-drag induced Skyrmion Hall effect. Possible experimental manifestations of this effect are also discussed. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2501.10998 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2501.10998v2 Announce Type: replace Abstract: Kagome superconductors AV$_3$Sb$_5$ (A=K, Rb, Cs) have sparked considerable interest due to the presence of several intertwined symmetry-breaking phases within a single material. Interestingly, in a recent experiment, magnetic hysteresis was observed in the superconducting state through magnetoresistance measurements in RbV$_{3}$Sb$_{5}$ [Nature Comm \textbf{17}, 1310 (2026)], providing strong evidence of a spontaneous time-reversal symmetry breaking superconducting state. The magnetic hysteresis, combined with crystalline symmetry, imposes strong constraints on the possible pairing symmetries of the superconducting state. In this work, we propose that RbV$_3$Sb$_5$ is a nodal topological superconductor with pseudo-spin-polarized Cooper pairs. The pseudo-spin-polarized superconducting domains resemble the properties of ferromagnetic domains and induce hysteresis. Moreover, the nodal topological superconducting state possesses Majorana flat band modes at the sample boundary, which can be detected by tunneling experiments. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2411.17815 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2411.17815v3 Announce Type: replace Abstract: Superconductivity in a partially filled flat band presents a vexing conceptual hurdle because the absence of a Fermi surface precludes a weak-coupling regime where one can extend insights from the Bardeen-Cooper-Schrieffer picture of a Fermi surface instability. We approach the strongly correlated problem of flat band superconductivity from the strong coupling limit of local attractive interactions on line-graph lattices, whose non-interacting bandstructures host exactly flat bands. In this limit, the pair kinetic energy which sets the superfluid stiffness is expected to scale inversely with the pair binding interaction. Here we demonstrate a striking counterexample. We show that when doped charges propagate on the line-graph of a lattice with strong pairing interaction, they bind into obstructed Cooper pairs whose motion is frustrated by destructive interference. As a result, the leading-order pair kinetic energy vanishes identically in the strong-coupling expansion, producing a flat bosonic band of compact localized pair states, zero superfluid stiffness at leading order, and an extensively degenerate many-body ground state manifold. At quarter filling, the frustrated pair dynamics maps onto a quantum dimer model with a $d$-wave resonating-valence-bond spin liquid ground state, which becomes exact at the analytically solvable Rokhsar-Kivelson point. The pairing Hamiltonian in this limit thus has a topologically ordered ground state with long-range entanglement and deconfined holon excitations. Interestingly, we find exact compact localized eigenstates and extensive degeneracies in the many-body eigenstates of this emergent dimer model. Our results establish a disorder-free mechanism for interaction-driven localization, in which strong pairing collapses the kinetic energy of Cooper pairs. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.15204 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15204v1 Announce Type: new Abstract: We study the penetration of an external magnetic field into a superconductor with collinear $d$-wave altermagnetic order. We demonstrate that instead of circular Abrikosov vortices, the magnetic field generates elliptical vortices with their major axis oriented along one of the crystallographic axis, along which the altermagnetic spin splitting is maximal. Upon reversing the component of the magnetic field parallel to the altermagnetic N\'eel vector, the vortices reorient towards the other crystallographic axis with maximal spin splitting. We demonstrate that this effect originates from an altermagnetism-induced anisotropy of the effective mass, which is controlled by the coupling between the external magnetic field and the N\'eel vector. As a consequence, a superconducting film hosting such altermagnetic order and containing pinning defects exhibits nonreciprocal magnetization curves under reversal of the magnetic field parallel to its N\'eel vector, due to the different vortex--vortex interaction energies for the two field orientations. Our results broaden the understanding of the coexistence of altermagnetism and superconductivity, both in materials hosting these orders intrinsically or in superconductor/altermagnet hybrid structures, and open new experimental avenues for exploring supercurrent vortices in these systems. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.15120 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15120v1 Announce Type: new Abstract: We extend the well-established action of the Higgs mode in $s$-wave superconductors to include quantum fluctuations (QFs). We find that already one-loop quantum corrections to the Higgs propagator shift its eigenfrequency below the superconducting energy gap $2\Delta$. Consequently, the Higgs mode appears as an undamped pole below the quasiparticle continuum, leading to drastically sharper experimental signatures. We demonstrate this by calculating two characteristic fingerprints of the Higgs mode, namely in Third Harmonic Generation (THG) and inelastic Raman scattering signals. More generally, gaps measured in $s$-wave superconductors with different experimental techniques (such as scanning tunneling microscope and Raman scattering) may be different due to fluctuation corrections. Since already arbitrarily weak QFs lead to the shift and to the new pole, our results shed some light on other amplitude modes even for systems with weak QFs, including charge density waves, (anti-) ferromagnets, or cold atom fermionic condensates. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.15054 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15054v1 Announce Type: new Abstract: Lifshitz invariant is a symmetry-allowed term in the Ginzburg-Landau free energy of an ordered phase, involving the order parameters and a single spatial derivative, which serves as a source of unusual optical responses. Here we introduce a ``type II" Lifshitz invariant for superconductors, which changes its sign under the particle-hole transformation and can be distinguished from the ordinary particle-hole even ``type I" Lifshitz invariant. We show that the type II Lifshitz invariant appears only in superconductors that break time-reversal symmetry and allows the Higgs mode to be visible in the optical conductivity spectrum. We provide a classification of all pairs of irreducible corepresentations of order parameters in the magnetic point groups that admit a type II Lifshitz invariant. We also numerically calculate the optical conductivity for various models of time-reversal symmetry broken multiband superconductors, finding agreement with the group-theoretical analysis. Our results establish a universal class of time-reversal symmetry broken superconductors hosting an optically active Higgs mode. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14623 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14623v1 Announce Type: new Abstract: This study maps the quantum landscape of superconducting diodes (SDs) \cite{nadeem23} onto the quantum technology architecture, which is currently constrained by fundamental challenges in control and scalability. In the existing non-integrated quantum technology hardware, control and scalability related issues emerge at two fronts: First, nonlinear and nonreciprocal circuit elements, which are essential building blocks for quantum processors, are often complex, bulky, and dissipative. Second, the temperature gradient between classical control electronics ($T_C\gtrsim$ K), which is also dissipative, and the quantum processor at cryogenic temperatures ($T_Q\sim$ mK) makes scalability even more challenging. The main focus is to reveal how the built-in nonlinearity, nonreciprocity, and quantum functionalities of SDs are significant for on-chip integrated circuit quantum electrodynamics (c-QED), enabling scalable integration of noise-resilient qubit and qubit-interfaces for efficient power delivery, coherent control and memory, high-fidelity readout, and quantum-limited amplification. To this end, this study will also shed light on how thermodynamic constraints and field effects can be harnessed within a quantum-enhanced SD platform, thereby enabling thermal compatibility between classical and quantum workflows, isothermal all-electrical control, and on-chip scalability. This perspective is expected to play a pivotal role in the advancement of superconducting circuit-based quantum hardware with temperature-matched classical, quantum, and hybrid workflows. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14578 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14578v1 Announce Type: new Abstract: Understanding and controlling vortex motion in superconductors are important both for suppressing dissipation in superconducting devices and for device applications that exploit vortices. In this work, we quantitatively imaged the stray magnetic field distribution of vortices in an NbN thin film by wide-field magnetic imaging using a perfectly aligned diamond NV ensemble. By continuously measuring while stepwise varying the applied magnetic field under local laser heating, we captured a rearrangement of the vortex configuration in real space and in real time over more than 100 min. The observed vortex rearrangement is consistent with a reduction of the pinning force due to local laser heating and with the Lorentz force exerted by shielding currents induced by the field variation. These results provide insight into vortex dynamics and suggest potential applications, including vortex exclusion from sensitive regions of superconducting devices and vortex positioning in vortex-based devices. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14485 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14485v1 Announce Type: new Abstract: We demonstrate a rapid, maskless fabrication method for superconducting terahertz Josephson plasma emitters (JPEs) based on direct ultraviolet laser micromachining of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi-2212) single crystals. Although machining debris is formed near the processed regions, uniform stacks of intrinsic Josephson junctions are preserved inside the crystal, enabling stable terahertz emission. Devices fabricated with Ag, Cu, and Cr electrodes all exhibited terahertz radiation, with Cu electrodes showing performance comparable to Ag while offering a low-cost alternative. Spectroscopic and polarization analyses indicate that the emitted radiation is elliptically polarized and dominated by the geometrical cavity resonance mode. Structural and electrical characterizations reveal that the machining width and depth are not limited by the optical spot size but are governed by the anisotropic thermal conductivity of Bi-2212, consistent with a thermally dominated laser ablation process. This direct laser micromachining approach provides a fast and versatile fabrication technique for JPEs and is broadly applicable to superconducting electronics and terahertz devices. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14395 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14395v1 Announce Type: new Abstract: We previously reported apparent ideal diamagnetism at ambient conditions in a graphene-n-heptane-permalloy system. At the same time, the experiments revealed inconsistent behavior, including signal freezing and occasional paramagnetic responses. Further measurements performed without graphene produced similar signals, indicating that graphene is not responsible for the observed effects. The results suggest that magnetic field redistribution caused by inhomogeneities in the permalloy foil and experimental geometry can mimic ideal diamagnetism in sub-milligauss measurements. These findings revise the interpretation of our earlier results and emphasize caution in interpreting ultra-low-field magnetic measurements. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2512.14414 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2512.14414v2 Announce Type: replace Abstract: We propose a single-layer tensor network framework for the variational determination of ground states in two-dimensional quantum lattice models. By combining the nested tensor network method [Phys. Rev. B 96, 045128 (2017)] with the automatic differentiation technique, our approach can reduce the computational cost by three orders of magnitude in bond dimension, and therefore enables highly efficient variational ground-state calculations. We demonstrate the capability of this framework through two quantum spin models: the antiferromagnetic Heisenberg model on a square lattice and the frustrated Shastry-Sutherland model. Even without GPU acceleration or symmetry implementation, we have achieved a bond dimension of nine and obtained accurate ground-state energy and consistent order parameters compared to prior studies. In particular, we confirm the existence of an intermediate empty-plaquette valence bond solid ground state in the Shastry-Sutherland model. We have further discussed the convergence of the algorithm and its potential improvements. Our work provides a promising route for large-scale tensor network calculations of two-dimensional quantum systems. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2511.06004 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2511.06004v2 Announce Type: replace Abstract: The ground state of the classical antiferromagnetic XX model in a magnetic field is calculated for spins mounted on the vertices of the icosahedron. The magnetization is characterized by two discontinuities as a function of the external field. For a wide field range above the first discontinuity the ground state is degenerate, with two spins related by spatial inversion aligned with the field and the rest forming two magnetization units in the form of pentagons. It is shown that the degeneracy originates from the coupling of the two pentagons, which introduces the triangle, associated with ground-state degeneracy, as an interaction unit in the icosahedron. The magnetization discontinuities are shown to evolve first from the coupling of isolated triangles and then from the coupling of the two spins related by spatial inversion. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.11678 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.11678v2 Announce Type: replace Abstract: The kagome lattice of spin-1/2 copper atoms in herbertsmithite is conjectured to sustain a quantum spin liquid state with spinon quasiparticles. Ideally, the kagome crystal planes are each separated by a plane of spinless zinc atoms. However, in real crystals some spin-1/2 copper atoms substitute randomly onto these inter-kagome zinc sites. Here we reconceptualize such 'impurity' atoms as quantum witness spins whose dynamics is designed to probe the spin liquid state. We then introduce spin noise spectroscopy to measure the frequency and temperature dependence of witness spin dynamics, demonstrating that their phenomenology is consistent with extensive interactions between witness spins mediated by propagation of spinons through a quantum spin liquid. Ultimately, a sharp transition occurs at around 260 mK, below which the properties of both spin noise and magnetic susceptibility suggest that the witness spins form a spin glass phase. Among theoretical models considered, we demonstrate that our observations are only consistent with spinon-mediated interactions between witness spins by either a Z2 or U(1) quantum spin liquid, with the former model more closely matching the data. Our work demonstrates that quantum mechanical witness spins may now conceivably be used as a widely applicable probe of quantum spin liquid physics. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.03967 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.03967v2 Announce Type: replace Abstract: We extend a recently defined measure of symmetry breaking, the entanglement asymmetry, to higher-form symmetries. In particular, we focus on Abelian topological order in two dimensions, which spontaneously breaks a 1-form symmetry. Using the toric code as a primary example, we compute the entanglement asymmetry and compare it to the topological entanglement entropy. We find that while the two quantities are not strictly equivalent, both are sub-leading corrections to the area law and can serve as order parameters for the topological phase. We generalize our results to non-chiral Abelian topological order and express the maximal entanglement asymmetry in terms of the quantum dimension. Finally, we discuss how the scaling of entanglement asymmetry correctly detects topological order in the deformed toric code, where 1-form symmetry breaking persists even in a trivial phase. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2505.21054 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2505.21054v3 Announce Type: replace Abstract: We present an iterative method for generating the complete set of self-energy Feynman diagrams at arbitrary order for the single-polaron problem with arbitrary linear coupling to the lattice. The approach combines a combinatorial representation of noncrossing diagrams, based on Dyck paths associated with Stieltjes-Rogers polynomials, with the constraints of the Ward-Takahashi identity to systematically incorporate vertex corrections. This construction yields a one-to-one correspondence between terms in the expansion based on Stieltjes-Rogers polynomials and diagrammatic contributions, and provides, through a sequence of simple steps, a closed, algorithmic framework for generating all diagrams of a given order, together with their relative weights. The method enables efficient, unbiased evaluation of diagrammatic series and improves the convergence of diagrammatic Monte Carlo by eliminating the need for stochastic weighting between different topologies. We further outline how the construction can be generalized to finite-density electron systems. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2504.06739 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2504.06739v3 Announce Type: replace Abstract: Kondo screening of local moments in normal metals typically leads to hybridized conduction and valence bands separated by a Kondo gap, resulting in an insulating state at half-band filling. We show a dramatic change of this scenario in a Dirac-semimetal-based correlated system -- a bilayer honeycomb lattice heterostructure where a local moment lattice is stacked on a Dirac semimetal breaking the inversion symmetry. This system is modeled by an extended Anderson honeycomb lattice involving the real-space dependence of major interlayer hybridization parameters on the relative sliding distance along the armchair direction. First, we unveil multiple Kondo scales and successive Kondo breakdown transitions in this correlated heterostructure under sliding. Second, we demonstrate the existence of a genuine selective Kondo screening phase which is stabilized near the A-B stack pattern and is accessible by applying interlayer voltage. Third, we find a nearly flat hybridized band located concomitantly within the Kondo gap, resulting in an unprecedented metallic state at half-band filling. This unconventional heavy fermion state is characterized by violation of Luttinger theorem and appearance of a Van Hove singularity at the Fermi energy. The general sliding-driven band structure landscape and the implications of our results for the broad context of multiorbital Kondo physics are briefly discussed. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14952 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14952v1 Announce Type: cross Abstract: The question of a possible quantum critical point lying inside of a superconducting phase is central for understanding unconventional superconductivity. In various unconventional superconductors, non-Fermi-liquid/'strange-metal' $T^{n}$ variations, with $n<2$, of the electrical resistivity have been identified as the signature of magnetic quantum criticality. However, a difficulty is to prove experimentally that a non-Fermi-liquid/'strange-metal' law identified at temperatures above the superconducting temperature is the signature of an intrinsic zero-temperature quantum critical regime. In the heavy-fermion paramagnet UTe$_2$, unconventional superconductivity develops in the vicinity of a metamagnetic quantum phase transition induced by a magnetic field, and the quantum critical magnetic properties are suspected to play a role for the superconducting mechanism. In this work, we present a comparative analysis of electrical resistivity data collected on two UTe$_2$ samples of different qualities, in magnetic fields tilted by angles $\theta\simeq35-40$~$^\circ$ from $\mathbf{b}$ to $\mathbf{c}$. Fits to the data have been performed either with a Fermi-liquid function $\rho=\rho_0+AT^{2}$ or with a non-Fermi-liquid/'strange-metal' function $\rho=\rho_0+A_nT^n$. Near to a superconducting phase induced beyond 40~T, non-physical residual resistivities $\rho_0<0$ are extracted from the $T^n$ fits, revealing that a 'hidden' Fermi-liquid $T^2$ regime may be ultimately recovered at low temperature. The results obtained here highlight the importance to investigate high-quality samples with low residual resistivity to confirm - or not - the presence of a suspected 'hidden' quantum critical behavior masked by superconductivity. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14701 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14701v1 Announce Type: cross Abstract: Ruddlesden-Popper nickelates offer a new route to high-temperature superconductivity beyond the cuprates and iron-pnictides. However, the electronic reorganization that enables superconductivity in bilayer nickelates remain unresolved, largely due to the difficulty of directly probing the superconducting phase. Here, we overcome this limitation by stabilizing superconducting (La,Pr)$_3$Ni$_2$O$_7$ thin films with a protective capping layer, thereby enabling direct spectroscopic access via X-ray absorption and resonant inelastic X-ray scattering. We resolve the evolution of in-plane and out-of-plane electronic states, spin and orbital excitations, and spin-density-waves across insulating, superconducting, and metallic regimes. Combining experimental results with theoretical analysis, we show that the in-plane $d_{x^2-y^2}$ states form an itinerant backbone, while superconductivity emerges only when coherent $d_{z^2}$-$p_z$-$d_{z^2}$ interlayer hybridization develops, accompanied by suppressed static spin order and strongly damped spin excitations. Oxygen stoichiometry and epitaxial strain both act on this interlayer channel, placing superconductivity within a narrow window of interlayer coherence and correlation strength. These findings identify the microscopic ingredients required for superconductivity in bilayer nickelates and provide a multiorbital picture of its emergence. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14859 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14859v1 Announce Type: new Abstract: Plasmon modes, their dispersion, and the onset of damping when approaching the electron-hole continuum are well understood when electron correlations are weak. However, we know little about how this picture is modified and what additional features emerge in strongly correlated materials. Here, we present a fully ab initio approach to plasmon excitations that combines density functional theory with dynamical mean-field theory, and we use it to reconcile controversial electron energy-loss spectroscopy results in Sr$_2$RuO$_4$. In particular, we show that electronic correlations reproduce the plasmon dispersion, while generating a large intrinsic width already below the electron-hole continuum. An additional high-energy peak reflecting transitions between incoherent features and a sharp increase of the plasmon's energy-momentum dispersion, akin to waterfalls in photoemission spectroscopy, are identified as genuine correlation effects. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14767 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14767v1 Announce Type: new Abstract: We investigate the ground-state magnetic structure of the spin-$1/2$ XXZ antiferromagnet on the triangular lattice in the easy-axis regime using the density-matrix renormalization group. By applying spiral boundary conditions, we exactly map finite $L\times L$ clusters onto one-dimensional chains while avoiding the spatial anisotropy inherent in cylindrical geometries. From symmetry-broken local magnetization profiles, we extract the three-sublattice moments and track their evolution with anisotropy. At the isotropic point, we obtain a positive sublattice moment of $0.21671$, consistent with previous numerical estimates. In the easy-axis regime, the ordered moments remain close to a zero-magnetization three-sublattice structure of the form $(2m,-m,-m)$ over a broad range of $\Delta$. Extrapolation in $1/\Delta$ shows that the positive sublattice moment stays well below the classical saturation value $1/2$, approaching $0.41873$ as $\Delta\to\infty$, while the magnitude of the negative sublattice moment approaches $0.20832$. We further compare the energies of the Y state and the up-down-down state and find that the Y state is favored at zero field. Independent thermodynamic-limit energy calculations, performed without assuming any particular ordered pattern, yield an energy consistent with the Y-state solution. These results show that the easy-axis ground state does not simply cross over to a trivially saturated collinear Ising state, but instead remains a nontrivial three-sublattice ordered state selected from the macroscopically degenerate Ising manifold by quantum fluctuations. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14695 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14695v1 Announce Type: new Abstract: Understanding how the interaction range and various types of disorder affect the level statistics of many-body quantum systems and lead to the emergence of many-body localization (MBL) is a challenging open frontier. We study the level statistics of a variant of the spin-$1/2$ Haldane-Shastry model with $1/r^{\alpha}$ interactions, where $\alpha{\geq}0$ parametrizes the range of the interactions, in the presence of position disorder and/or random magnetic fields. We find that neither position disorder nor random magnetic fields alone yields pristine Poisson statistics in this long-range interacting system; however, Poisson statistics emerge in their combined presence, suggesting the emergence of MBL when both types of disorder coexist. Interestingly, once random magnetic fields break the $SU(2)$ symmetry, the strength of the position disorder, $\delta$, appears to play an important role, as evidenced by an approximate scaling collapse of the disorder-averaged gap ratios that is parametrized in terms of a single parameter, $\alpha \delta$. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14415 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14415v1 Announce Type: new Abstract: Correlated transition metal oxides present exciting prospects as switches or memory and storage devices owing to the possibility to control electronic properties using various external stimuli. While their complex behaviour is known to stem from interplay between electronic correlations, atomic structure and orbital physics, they remain poorly understood on the microscopic level. Here, we investigate such origins as a function of temperature and pressure in the transition metal oxide Ti3O5. We find that the insulating room-temperature phase is characterized by one-dimensional zig-zag chains composed by two types of titanium dimers forming orbital selective valence bonds. At the thermal phase transition, one type of titanium dimer breaks up, resulting in an insulator to metal transition with a large orbital repopulation between the two states. Moreover, optical spectroscopy reveals that an additional pressure-driven insulator to metal transition occurs in Ti3O5 at room temperature. The phenomenology of this novel pressure-induced metallic transition is completely different from the insofar studied transitions and results from a competition between intra- and inter-dimer hopping. Our combined results suggest that Ti3O5 is a prototypical correlated transition metal oxide, where both correlations as well as orbital interactions need to be considered to fully understand the evolution of the electronic states. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14369 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14369v1 Announce Type: new Abstract: Twisted bilayer graphene provides a paradigmatic platform for exploring the interplay between electronic topology and strong correlations. Within the topological heavy fermion model [Song and Bernevig, Phys. Rev. Lett. 129, 047601 (2022)], topology and electron interactions are brought together by including a weak hybridization between the bands of itinerant $c$- and localized $f$-electrons. Hybridization infuses concentrated Berry curvature into the $f$-band, while leaving it flat. These band features have motivated recent proposals of a Mott semimetal phase above the flavor-ordering temperature at charge neutrality. In this work, we develop an analytic theory of the quasiparticle dispersion and lifetime in the Mott semimetal. We reformulate the interacting flat-band Hamiltonian as an on-site Hubbard interaction defined on a set of non-orthogonal orbitals, and compute the electron Green's function using the equation-of-motion method, in close analogy with the Hubbard-III approximation. Unlike the conventional Hubbard model, in our case this approximation is controlled by a well-defined small parameter in the theory. We evaluate the electron self-energy and demonstrate the emergence of well-defined low-energy quasiparticles with the dispersion and relaxation rate proportional to the interaction strength. The quasiparticle spectrum is well-resolved in energy and in momentum down to the very vicinity of the Fermi level. Our results illustrate unconventional spectral properties arising from strong correlations and nontrivial quantum geometry, and have direct relevance for spectroscopic probes such as quantum twisting microscope experiments. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14367 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14367v1 Announce Type: new Abstract: We develop a general framework to calculate the many-body density of states (DOS) of isolated and interacting quantum systems. Based on the generalized coherent state formalism and the Simon-Lieb bounds for a quantum partition function, our method provides a general method of calculation for the DOS in high-dimensional irreducible sectors. This framework further provides rigorous bounds for the ground state energy in each sector and enables the calculation of microcanonical observables across the entire spectrum. Using the Lipkin-Meshkov-Glick (LMG) model as a test bed, we validate our framework by successfully identifying quantum phase transitions (QPTs) and excited-state quantum phase transitions (ESQPTs) across spin sectors. Unlike existing model-specific numerical or analytical techniques, our formalism relies on general underlying symmetries, making it broadly applicable. Applying our method to the ferromagnetic transverse field Ising chain with power law interactions, we demonstrate that its highest-spin-sector DOS is qualitatively identical to that of LMG-type Hamiltonians. Our work establishes a versatile and computationally efficient bridge between algebraic structure and many-body thermodynamics. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14303 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14303v1 Announce Type: new Abstract: Twisted bilayer graphene near integer fillings hosts correlated single-particle excitations whose dispersion and linewidth are increasingly accessible experimentally. We study these excitations using the topological heavy-fermion model, which captures both strong correlations and band topology of twisted bilayer graphene. In the decoupled limit, where both the single-particle fc hybridization and the Hund coupling between f and c electrons are absent, the model admits exact solutions in which free Dirac fermions coexist with interacting f electrons that form zero-width Hubbard bands. By treating the fc hybridization and Hund coupling perturbatively around this solvable limit, we obtain analytical results for the single-particle self-energy. From the resulting self-energy, we derive explicit expressions for both dispersion renormalization and scattering rates of both Hubbard-band excitations and low-energy Dirac modes, thereby establishing an analytical framework for understanding correlated excitations in twisted bilayer graphene. We analyze the scattering of the two kinds, Gamma3 and Gamma1,2, of Dirac electrons and find that they arise from different mechanisms. We also briefly investigate the effect of strain. Finally, we compare these analytical expressions with DMFT results for the same model. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14295 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14295v1 Announce Type: new Abstract: In many strongly correlated electron systems, non-Fermi liquid behavior and unconventional superconductivity can be viewed as emerging from an effective 4-fermion interaction with a singular frequency dependence. A pairing instability in such a system is qualitatively different from that in a Fermi liquid and generally gives rise to multiple pairing states with topologically distinct gap functions. However, in the systems studied so far, a topologically trivial solution has the lowest energy. Here we show that a repulsive Hubbard-type interaction with a finite cutoff added to a model with a singular dynamical interaction selects, in some parameter range, the theretofore subleading, topologically nontrivial solution. We consider a minimal model that displays this behavior and show that the transformation between the topologically trivial and nontrivial gap functions necessarily occurs via an intermediate phase with topology-induced breaking of time-reversal symmetry. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14294 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14294v1 Announce Type: new Abstract: The Migdal-Eliashberg theory (MET) describes electrons interacting with phonons in the adiabatic limit when the phonon Debye frequency is much smaller than the Fermi energy. A conventional belief is that MET holds even at strong coupling, when electron self-energy is large, and breaks down only near the point where the dressed phonon spectrum softens to near zero. We analyze numerically and analytically a different option -- collapse to a polaronic/bipolaronic ground state. The last scenario has never been analyzed in precise quantitative terms for a generic electron density. Using variational considerations, we establish rigorous upper bounds on the coupling $\lambda$, at which a FL state transforms into the bipolaron/polaron state. We show that at small and near-maximum densities, this happens well before a dressed phonon softens. This is true both in 2D and 3D systems; in the latter the upper bound on $\lambda$ tends to zero in the limit of small or near-full density. We present analytical reasoning for this behavior based on hints extracted from exact diagrammatic treatment of the on-site Holstein model for the spin polarized case and argue that polarons are produced by fermions with energies comparable to the bandwidth; i.e., polaron formation is outside the realm of MET. Closer to half-filling, the leading instability upon increasing $\lambda$ is towards a charge-density-wave state (CDW), and there exists a strong coupling regime of MET near this instability, while the polaron/bipolaron state develops at larger $\lambda$ out of a CDW-ordered state and inherits a CDW order over some range of coupling. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14293 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14293v1 Announce Type: new Abstract: It is widely believed that in an adiabatic limit a Fermi liquid state of an electron-phonon system described by Migdal-Eliashberg theory remains stable before a dressed phonon softens. Using Holstein model as a prototypical example and variational/analytic considerations we demonstrate that in a wide range of fillings both in 3D and 2D, a polaronic/bi-polaronic state emerges before phonon softening; at small filling in 3D this happens already at weak coupling. We show that a polaronic/bi-polaronic state emerges, upon increasing coupling, via an intermediate pseudogap-type mixed state, in which some fermions regain Fermi liquid behavior, yet Luttinger theorem is broken. At even larger couplings the density of states gradually approaches its form in the atomic limit. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14289 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14289v1 Announce Type: new Abstract: Unlike conventional charge-2e superconductors, a charge-4e superconductor exhibits long-range coherence of electron quartets rather than Cooper pairs. Clear zero-temperature realizations of charge-4e superconductivity remain rare. Here, we investigate the zero-temperature phase diagram of the attractive SU(4) Hubbard model with numerically exact, large-scale quantum Monte Carlo (QMC) simulations overcoming major technical hurdles. We identify both charge-2e and charge-4e superconducting phases. Upon increasing interaction, charge-2e correlations are suppressed and eventually vanish, while the charge-4e correlations remain robust and converge with system size, signaling the onset of a quartet-condensed phase. Interestingly, across the charge-2e--charge-4e transition, single electrons remain gapped, while charge-2e correlations exhibit a scaling behavior inconsistent with a conventional Landau description. These features are naturally captured by a fractionalized framework in which the physical charge-2e order parameter is a composite field coupled to an emergent non-Abelian gauge structure. We formulate an Sp(4) gauge-Higgs theory that realizes deconfined quantum pseudocriticality between the Higgs (charge-2e) phase and the confined (charge-4e) phase. The Sp(4) gauge-Higgs theory yields pseudocriticality through a fixed-point collision, and its one-loop collision-point exponents quantitatively track the QMC results. Our results establish charge-4e superconductivity as a bona fide zero-temperature phase, provide a simple model for future studies in a numerically exact framework, and reveal an unconventional route to superconducting criticality. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14286 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14286v1 Announce Type: new Abstract: We show that the spin conductivity of a metal approaching a ferromagnetic quantum critical point exhibits divergent fluctuation corrections. This effect arises from critical spin fluctuations and constitutes a spin analog of the Aslamazov-Larkin theory of paraconductivity in superconductors. The spin current is derived in linear response within a Gaussian-level treatment of the effective action for a system with easy-plane magnetic anisotropy. We demonstrate the consistency of our spin transport theory by showing that it (i) fulfills the Ward identity and (ii) yields vanishing spin stiffness in the normal state. The critical enhancement of the spin conductivity is interpreted as incipient spin superfluidity in the quantum critical region. This is further supported by an intuitive picture based on the current-loop representation of the easy-plane ferromagnet. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.03796 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.03796v2 Announce Type: replace Abstract: We investigate the formation of bound states between dark-antidark solitary waves in two-component dipolar Bose-Einstein condensates. The excitation spectrum contains density and spin branches, and a rotonic feature of the spin branch enables long-range soliton interactions, giving rise to multiple bound states for a single pair, each with a distinct separation. We show that these bound states originate from periodic modulations of the inter-soliton potential, while individual solitons are surrounded by spatial spin-density oscillations. Both features provide direct signatures of the spin roton. Collisions between unbound solitons probe this potential, with dipolar interactions enforcing universal bouncing at low velocities, independent of soliton sign, whereas nondipolar solitons may either transmit or bounce. This distinct behavior offers a realistic path to confirming spin rotons experimentally. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.15234 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15234v1 Announce Type: cross Abstract: Magnetic correlations of doped Mott insulators hold the key to the unusual characteristics of many quantum materials. Recent experiments with ultracold atoms in optical lattices have provided new information about the magnetic properties of the Fermi-Hubbard model on a square lattice. We demonstrate that recent measurements indicate that a single doping-dependent energy scale determines both static correlations and dynamical response of these systems. To understand these experimental findings, we employ a self-consistent formalism to describe the coupling between antiferromagnetic magnons and doped holes, and we uncover the emergence of a universal magnetic energy scale at finite doping, which we denote by $J^*$. We present the single- and two-magnon spectral properties at finite doping and discuss the appearance of a bimagnon peak in lattice-modulation spectroscopy, at frequencies set by $J^*$. Furthermore, we argue that this same energy scale sets the onset of pseudogap phenomena, leading to the hypothesis $k_BT^* = c J^*$, with $c$ an order one number. We identify another low-energy scale emerging from our analysis of magnetic excitations, and argue that it controls the stability of N\'{e}el order at the lowest temperatures, ultimately driving a transition to an incommensurate spin-density-wave at finite doping. We discuss the relation between this low-energy scale and the nature of fermionic quasiparticles. Our analysis suggests that stability of the commensurate antiferromagentic phase at finite doping can be controlled experimentally by introducing additional quasiparticle broadening via disorder or low-frequency noise. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.15056 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15056v1 Announce Type: cross Abstract: The condensation of electron quartets, known as charge-4e superconductivity (SC), represents a novel quantum state of matter beyond the standard paradigm of Cooper pairing. However, concrete microscopic models realizing this phase in two dimensions remain a central challenge. Here, we introduce a non-engineered and sign-problem-free model, unambiguously demonstrating the emergence of a robust and high-temperature charge-4e SC phase using unbiased quantum Monte Carlo simulations. At zero temperature, the phase diagram reveals that charge-4e SC is the primary ground state in the strong-coupling regime. At finite temperature in the absence of charge-2e SC, we identify charge-4e SC through a Berezinskii-Kosterlitz-Thouless transition, marked by a universal jump in the superfluid stiffness consistent with a condensate of charge 4e. Remarkably, the transition temperature Tc increases nearly linearly with interaction strength, providing a robust mechanism for high-Tc quartet superconductivity. Furthermore, spectral analysis reveals a prominent pseudogap above Tc arising from strong phase fluctuations. Our results establish a canonical and numerically exact model system for charge-4e superconductivity, offering crucial guidance for its realization in experimental platforms such as moir\'e materials and ultracold atomic systems. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14721 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14721v1 Announce Type: cross Abstract: The Casimir-Polder (CP) effect -- the force between a neutral atom and an uncharged conducting plate in empty space -- is an intriguing consequence of quantum vacuum fluctuations. The typically attractive CP potential crosses over from a scaling of $z^{-3}$ at short separations to $z^{-4}$ at long distances, where retardation effects due to the finite speed of light become important. At intermediate distances, where the atom--surface separation is of the order of the wavelength of the dominant atomic transition, experiments have so far relied on indirect methods, such as diffraction or quantum reflection, to observe the CP effect. Here, we directly reveal the CP force between strontium atoms and a dielectric surface via the induced shifts in the atomic energy levels in the intermediate regime. We spectroscopically probe the CP-induced kHz-frequency shift of ultracold atoms confined by a magic-wavelength optical lattice at 189(2)~nm from the surface -- on the scale of the dominant 461-nm transition. Our measurements agree well with QED calculations and differ from the short-range approximation, while excluding the long-distance one. This paves the way for studying the CP effect across various surface properties and geometries, as well as exploring the tensor nature of the atom-surface potential -- all important for the development of hybrid atomic optical-magnetic quantum devices. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.15095 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15095v1 Announce Type: new Abstract: Kardar-Parisi-Zhang (KPZ) scaling has been observed in discrete polariton lattices, enabled by engineered band structures that stabilize the condensate. Whether this universality extends to intrinsically continuous systems with natural noise regularization remains an open question. We propose and numerically demonstrate KPZ scaling in a continuous quasi-one-dimensional polariton condensate stabilized by optical confinement in the transversal direction. Large-scale simulations of the stochastic Gross-Pitaevskii equation, with experimentally relevant parameters, reveal temporal and spatial scaling exponents of the two-point phase correlation function betaC = 0.30(5) and alfaC =0.46(8), and Tracy-Widom one-point phase fluctuation statistics, yielding robust KPZ dynamics intrinsic to the continuous polariton fluid. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14771 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14771v1 Announce Type: new Abstract: The plethora of possible ground states of spinor bosons placed in an external lattice and a cavity is revisited. We discuss the simplest case when the external lattice nodes coincide with the antinodes of the cavity field. We analyze the problem within the grand-canonical mean-field approach, considering both the homogeneous system and the nonhomogeneous case with a harmonic trapping potential. Due to the spin degree of freedom, in the homogeneous case we treat the system in a twofold manner: we impose the physically relevant total-magnetization constraint, while also discussing the minimization landscape for the full unconstrained problem. In the latter, by combining analytical arguments with numerical calculations based on the Gutzwiller ansatz, we show that the system exhibits two types of magnetic phases: an antiferromagnetic Mott insulator (AFM) and a ferromagnetic density wave (FDW). In addition, three distinct supersolid phases emerge, characterized by different patterns of spin and density imbalances. In case of the zero total magnetization, only two of the three supersolid regimes survive, and the FDW phases are replaced by entangled density waves (EDW). These new ground states present density-modulated superpositions of the underlying spin components of the bosons. Finally, we present the phase diagram of the trapped system, which is directly relevant for future experiments. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14559 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14559v1 Announce Type: cross Abstract: Chitosan is a highly versatile and sustainable polymer with a broad range of potential biological and materials engineering applications. Despite its versatility, the native brittleness of chitosan limits its broader utilization. This limitation can be addressed by blending chitosan with small-molecule additives to modulate its thermomechanical properties. We employ molecular dynamics (MD) simulations to investigate the mechanism underlying antiplasticization followed by plasticization at increasing water content. Decomposition of the elastic moduli reveals a competition between weakened polymer-polymer interactions and enhanced polymer-water interactions, with their relative strengths governing the resulting properties. We introduce a simple model incorporating dynamically accessible free volume regions as a key driver of polymer mobility, effectively capturing the (anti-)plasticization of elastic properties. We show that accessibility of free volume regions is enabled by connectivity of additive-accessible volume regions. This study provides new insights into the molecular interactions that dictate the properties of chitosan-water mixtures and may inform the rational design of chitosan-based materials and other hydrated biopolymers. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14183 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14183v1 Announce Type: cross Abstract: Thermal conductivity of Earths lower mantle controls heat transfer across the core-mantle boundary (CMB) and strongly influences mantle convection. We report direct measurements of the thermal conductivity of single-crystal ferropericlase (Mg$_{1-x}$Fe$_x$O, $x = 0.09$-0.13), the second most abundant lower-mantle mineral, using optical laser flash and X-ray free-electron laser heating in diamond-anvil cells up to $\sim2200$~K and 130~GPa. These experiments provide the first conductivity data for ferropericlase at simultaneous lower-mantle pressures and temperatures. A marked reduction in conductivity between 60 and 100~GPa at $\sim1700$~K is consistent with the iron spin crossover. Combined with our previous results for Fe- and Fe,Al-bearing bridgmanite, the data define a lower-mantle conductivity profile that increases with pressure to $\sim10$~W\,m$^{-1}$\,K$^{-1}$ near the CMB, constraining mantle heat flux, plume buoyancy, and long-term geodynamic evolution. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15175 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15175v1 Announce Type: new Abstract: By applying our methodology, we propose a defect in 4H-SiC which combines a Si vacancy and a C atom substituted with S (VSiSC) to have a spin-triplet ground state with the spin qubit functionality. Our calculations confirm that all configurations of the defect have a dynamically and thermodynamically stable triplet ground state and higher energy singlet states, essential for the spin-qubit polarization cycle. From GW calculations, we found that the electronic states associated with the defect form sharp and isolated peaks within the band gap for both triplet and singlet states. Further Bethe-Salpeter-equation calculations show that all considered configurations have intense optical excitations in the near infrared spectrum range. Analysis of the excitation energies and rates indicate that the VSiSC defect can be an excellent optically controlled spin qubit. Crucially, the host elements and the dopant have high-abundance isotopes with zero nuclear spin ensuring high spin-coherence time of the qubit. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15156 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15156v1 Announce Type: new Abstract: In this study, we present a comprehensive analysis of the Raman active phonon modes in orthorhombic LaInO$_3$ based on a combination of polarization-angle resolved Raman spectroscopy and density functional theory calculations. By using backscattering from multiple crystallographic surface orientations and employing a full symmetry analysis, we identify and assign most of the Raman-active $\Gamma$-point phonons to their irreducible representations of the D$_{\rm{2h}}$ point group. A multidimensional hyperspectral fitting procedure allows us to extract the relative Raman tensor elements from the angular dependence of the scattering intensities, even for strongly overlapping modes. First-principles calculations yield the phonon dispersion along high-symmetry directions, the phonon densities of states, and atomic displacement patterns, which are found to be in good agreement with the experimental mode frequencies. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15131 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15131v1 Announce Type: new Abstract: A limited remanent polarization (Pr) in HfO2-based FeRAM remains a key obstacle to density scaling and reliability, while material and process optimizations offer only incremental improvements. This limitation fundamentally originates from the thickness-constrained switchable polarization and the intrinsic polarization ceiling of HfO2-based ferroelectrics. Here, we propose an all-ALD-grown vertical complementary FeRAM (VCF) architecture, in which the top and bottom stacked FeRAM cells maintain complementary polarization. This complementary dipole configuration converts the readout from a single-layer polarization response into a differential polarization summation, thereby amplifying the effective charge window without increasing the switching field of each individual layer or incurring area overhead. Viewed from top to bottom, an "up-down" polarization pair stores logic '1', whereas a "down-up" pair stores logic '0'. Using a complementary polarization write-read scheme, the VCF achieves an effective differential polarization above 100 uC/cm^2 and retains above 90 uC/cm^2 after 1e10 switching cycles without electrical breakdown. Robust retention (longer than 1e4 s at 85 degC) and strong disturb immunity are demonstrated, with an effective differential polarization above 80 uC/cm^2 under a V/3 scheme after 1e6 disturb pulses. Array-level operation is validated in a 5 x 5 selector-free crosspoint array. The performance enhancement of the VCF arises from the co-optimization of the all-ALD-grown process, device architecture, and operation scheme, enabling high density, a wide memory window, and strong reliability for scalable FeRAM integration. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.15081 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15081v1 Announce Type: new Abstract: Since its discovery, ferroelectric hafnia has been extensively studied due to its CMOS-compatibility and ability to remain polarized at sub-10 nm thicknesses. The ferroelectric behaviour is generally attributed to a polar orthorhombic (OIII) phase. However, a second polar phase with rhombohedral symmetry (R-phase) has also been reported in epitaxial films. The nature of the R-phase remains disputed due to the subtle differences with the OIII-phase when probed by standard thin film characterisation techniques. Given the functional properties of ferroelectrics are crucially determined by the crystal symmetry, resolving this matter is imperative. In this work, we settle the controversy through extensive 3D reciprocal space surveys made possible via synchrotron-based grazing incidence diffraction from epitaxial films of both phases. These experiments, together with direct comparison of their temperature dependence and electrical responses, conclusively establish them as two distinct phases and provide insight into their key characteristics. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14976 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14976v1 Announce Type: new Abstract: Non-van der Waals two-dimensional (2D) materials derived from strongly bonded non-layered crystals have recently emerged as a novel and rising platform for nanoscale research. While uncovering and tuning their (opto-)electronic, catalytic, and magnetic properties has been the focus of intense research, the impact of spin-orbit coupling (SOC) onto their electronic structure has not yet been explored in detail. Studying these effects is, however, particularly relevant due to their surface cation termination and the presence of heavy elements in several representative compounds. Here, we investigate the effect of SOC onto the electronic structure of 2D AgBiO3, NaBiO3, and SbTlO3. While the first two systems show negligible band renormalization upon inclusion of relativistic effects around the band gap, SbTlO3 showcases a large SOC induced splitting (229meV) for the lowest conduction bands associated with a band inversion. Substitution of Tl with Pb forming SbPbO3 brings the band-inverted feature to the Fermi level. Analysis of topological invariants and investigation of edge states of zig-zag and armchair ribbons within the 200meV gap confirms the topological nature of the band splitting. Our work thus establishes a foundation for the systematic study of robust non-van der Waals 2D topological insulators. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14947 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14947v1 Announce Type: new Abstract: Altermagnets are a new class of magnets accompanying global time-reversal symmetry breaking (TRSB) without net magnetization. The TRSB results in formation of novel altermagnetic domains. Features of altermagnetic domains, in particular their responses to external stimuli, are essentially important but yet unexplored. Here, we report visualization of bulk altermagnetic domains in MnTe based on scanning magneto-optical Kerr-effect microscopy using telecom infrared wavelength. We found two distinct TRSB domains with large Kerr rotations that do not scale with its tiny bulk magnetization. We also revealed controllability and stability of domains against magnetic or thermal perturbations. Our first observation of altermagnetic domains using a laboratory-scale simple optical technique showing their movable nature provide firm bases for future fundamental and application studies of altermagnets. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14894 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14894v1 Announce Type: new Abstract: We investigate optically induced phase transitions in the two-dimensional (2D) ferroelectric (FE) material Nb2O2I4 using real-time time-dependent density functional theory (rt-TDDFT). Our results demonstrate that tailored laser pulses can activate specific coherent phonon modes. Specifically, the anharmonic atomic distortions of the A1-1 and A1-2 modes at the {\Gamma}-point facilitate the reversal of in-plane polarization. By fine-tuning laser parameters, additional phonon modes at both the Y and {\Gamma} points are excited. The resulting nonequilibrium atomic dynamics enable the formation of previously unreported ferroic phases, including three antiferroelectric (AFE) phases and one ferrielectric (FiE) phase. Notably, these optically induced phases can be reverted to the initial FE state using appropriate techniques. This controllable reversibility among multiple ferroic phases positions 2D Nb2O2I4 as a highly promising candidate for next-generation electronic storage applications. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14845 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14845v1 Announce Type: new Abstract: Magnetoacoustic devices that harness the strong coupling between acoustic waves and magnons have emerged as a promising platform for energy-efficient spintronics. Laser-generated pulsed surface acoustic waves (SAWs) are particularly attractive for such applications, offering broadband frequency content up to the gigahertz (GHz) range, remote excitation without lithographic patterning, and surface localization for efficient on-chip integration. In this work, we present a comprehensive experimental study of laser-generated SAW pulses in the Fe49Rh51/MgO(001) system. A thin film of the near-equiatomic FeRh alloy serves both as an opto-acoustic transducer and as a mechanical load that modulates SAW propagation. The antiferromagnetic to ferromagnetic phase transition in FeRh, occurring slightly above room temperature, is accompanied by abrupt changes in its elastic properties, enabling controlled modification of the SAW excitation efficiency and dispersion characteristics by tuning the sample temperature and laser fluence. Using 160 fs laser pulses for excitation and time-resolved Sagnac interferometry for detection, we evaluated key SAW parameters, including amplitude, spectral content, phase and group velocities, and their in-plane anisotropy. Particular emphasis is placed on the dispersion relation and its anisotropy, which govern the coherent interaction between phonons and magnons and are determined primarily by the FeRh film. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14831 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14831v1 Announce Type: new Abstract: In this systematic density functional theory study, we compare a standard gradient corrected functional (PBE) with a long-range hybrid functional (HSE06), with and without correction for the dispersion forces, relatively to their ability to correctly reproduce structural and electronic properties of different bulk 3D C3N4 phases, encompassing diamond- and graphitic-like models. Corrugation is found to provide further stabilization to the layered structures with all methods. We observe that HSE06-D3 method provides results in good agreement with experimental data and with more sophisticated G0W0 calculations. Based on that, we exploited the method to investigate the nature of the bulk triplet excitons in these C3N4 structures to evaluate the S0-T1 energy difference, the selftrapping triplet exciton energy and the photoluminescence emission energy, since this is a promising vis-light photocatalyst. Nanostructuring (0D and 2D) is another relevant aspect of these materials in practical applications, therefore we have considered the effect of single or multilayer exfoliation or space confinement in nanoparticles. Finally, we also discuss how the introduction of extrinsic dopants (e.g. S atoms) in the nanostructures modifies the atomic and electronic structure. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14821 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14821v1 Announce Type: new Abstract: We present a study of the melting dynamics of a two-phase eutectic solid. In situ, thin-sample experiments using a transparent eutectic alloy and two-dimensional phase field simulations calibrated for the very same alloy are combined to assess pattern formation during directional melting in a temperature gradient. Depending on the melting velocity $V_m$ and the spacing $\lambda$ of the pre-solidified lamellar microstructure, an unexpectedly rich diversity of melting patterns is observed, with good agreement between experiments and simulations. We unravel the different physical mechanisms leading to this diversity, and establish the scaling behaviors of (i) the penetration of the liquid along the solid-solid interface at large $V_m$, (ii) the thickening of the primary-phase fingers at low $V_m$, and (iii) a period-doubling instability for small $\lambda$ values. Our study provides a fundamental basis for further investigations of eutectic melting, including additive manufacturing during which melting/solidification cycles take place. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14776 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14776v1 Announce Type: new Abstract: Altermagnet-based heterojunctions have demonstrated magnetoresistive effects in experiments, however, a predictive theoretical model for non-ferromagnetic structures has remained elusive. In this work, we develop a tunneling-based spin-transport theory that explicitly incorporates the transverse-wavevector ($\bf{k}_\|$)-dependent spin polarization of an altermagnet's transport channels, enabling the prediction of giant tunneling magnetoresistance (TMR). Based on the theory, we predict that the altermagnet KV$_2$Se$_2$O can reach the extreme limit of magnetoresistance. By performing first-principles transport calculations, we verify that magnetic tunnel junctions using the metallic KV$_2$Se$_2$O as the electrodes and few-layer MgO as the spacer exhibit zero-bias magnetoresistance larger than $7.57\times10^7$\%, which is robust against the bias and thickness of the spacer. Our research provides a quantitative design principle for next-generation spin-electronic devices and establishes KV$_2$Se$_2$O/MgO/KV$_2$Se$_2$O as a leading candidate material system for room-temperature ultra-high-density non-volatile memory. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14764 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14764v1 Announce Type: new Abstract: Rutile RuO$_2$ has attracted great interest recently, as its magnetic ground state remains controversial. Experimental studies have reported either nonmagnetic or altermagnetic (AM) ground states in different crystalline samples of RuO$_2$, highlighting the need for a reasonable explanation to resolve this contradiction. In this study, density functional theory calculations are performed to reveal the correlation-sensitive and strain-dependent magnetism of bulk RuO$_2$. On one hand, multiple AM phases with different magnitudes of the spin magnetic moment are identified in the Hubbard parameter space for RuO$_2$. On the other hand, when appropriate strains which significantly change the crystal cell volume are applied, the ground state of RuO$_2$ can undergo transitions between the nonmagnetic state with no spin splitting and the magnetic states with spin splitting in the band structure. These findings not only demonstrate intriguing physics in 4d-electron-correlated RuO$_2$, but also retain its potential for spintronic applications. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14750 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14750v1 Announce Type: new Abstract: Mound formation on flat and miscut crystal surfaces exhibits distinct growth behaviors. While mound structures are the predominant feature on flat surfaces, miscut surfaces display a smooth transition from meandered patterns to three-dimensional mounds, depending on both internal and external conditions. We investigate this morphological evolution-from meander-like surface patterns to faceted pyramidal structures-using a vicinal Cellular Automata modeling framework. The transition is shown to be governed by the competition between the Ehrlich-Schwoebel barrier and adatom mobility on terraces. Under moderate barrier strengths and sufficiently high terrace diffusivity, the system demonstrates a reversible transition from mounded configurations to regular step meandered patterns. This reveals a complex interplay between kinetic barriers and mass transport. Our simulations cover a wide range of growth conditions, including variations in deposition flux, surface diffusion rates, temperature, and miscut angle. By applying the height-height correlation function, we calculate the correlation lengths along and across the steps and analyze their scaling behavior. These results offer insight into the continuum pathways that connect distinct classes of surface structures and provide a unified framework for describing pattern evolution across different crystal growth regimes. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14680 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14680v1 Announce Type: new Abstract: Electroforming of metal-oxide-metal memristors is generally attributed to the creation of oxygen-vacancy filaments within the oxide, with noble metal electrodes such as Pt and Au remaining chemically inert. Here, we demonstrate that electroforming and subsequent operation of Pt/NbOx/Nb2O5/Pt devices can induce an unexpected and highly correlated redistribution of both oxygen and platinum. Time-of-flight secondary ion mass spectrometry reveals a filamentary pathway characterized by micrometer-scale oxygen enrichment extending from the Nb2O5 layer through NbOx and deep into the Pt top electrode. Surprisingly, this is accompanied by the formation of a Pt-rich filament penetrating the oxide stack along the same filamentary path. Finite-element and lumped-element modelling show that current-controlled negative-differential-resistance operation produces localized Joule heating and high-frequency thermal cycling, which strongly enhances oxygen migration and enables thermally assisted Pt diffusion along vacancy-rich pathways. These findings reveal a previously unrecognized metal-ion transport mechanism in NbOx memristors and highlight the critical role of post-forming electrical dynamics in determining filament chemistry, stability, and device reliability. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14554 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14554v1 Announce Type: new Abstract: Mg-IV-N\textsubscript{2} compounds with IV=Si, Ge, Sn are ultra-wide band gap semiconductors with various potential electronic and optoelectronic applications. They share the \textit{Pna}2\textsubscript{1} space group crystal structure. Here we present Density Function Perturbation Theory (DFPT) calculations of the vibrational modes of these materials. We focus on the vibrational modes at the zone center to establish the relation between vibrational modes and their corresponding point-group symmetries, which determine the Raman and infrared spectra but also report the full Brillouin zone phonon dispersions and density of states. We also determine the piezoelectric tensor and the elastic compliance tensor. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14509 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14509v1 Announce Type: new Abstract: As the number of theoretically predicted materials continues to grow, it becomes increasingly important to assess not only their thermodynamic stability but also their kinetic viability under realistic synthesis conditions. In this study, we investigate the hypothesis that the kinetic persistence of a metastable polymorph is related to the topography of the potential energy landscape separating it from lower energy phases. To accomplish this, we develop a new method for identifying diffusionless transformation pathways between metastable polymorphs and their ground-state counterparts and discuss the energetics of those pathways with respect to the experimental observation of each phase. This algorithm is underpinned by the recently developed Crystal Normal Form, which provides a graph representation of crystal configuration space and supplies the substrate for our pathfinding algorithm. We apply this method to the titanium dioxide system which contains the well-known anatase, rutile, and brookite phases in addition to a number of hypothetical metastable polymorphs. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14470 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14470v1 Announce Type: new Abstract: \textit{Ab initio} pseudo-atomic orbital (PAO) Hamiltonians express the electronic structure of a solid in a compact, localized basis that spans the same Hilbert space as a conventional Slater--Koster tight-binding model, thereby providing an exact \textit{ab initio} representation without any loss of accuracy. Building on this correspondence, we develop an environment-dependent tight-binding (EDTB) framework in which Slater--Koster hopping integrals are augmented with bond-screening functions that capture the local coordination environment. All parameters are determined by fitting to the PAO eigenvalue spectrum across multiple atomic configurations simultaneously, which breaks the degeneracy between screening and hopping parameters and yields physically meaningful, transferable models capable of generating Hamiltonians for large systems with \textit{ab initio} precision. We demonstrate the efficiency and accuracy of the approach on four prototypical systems: bulk platinum, silicon surfaces, Si/Ge~[001] superlattices, and twisted bilayer graphene with up to $4{,}324$ atoms. The method is implemented in the \paoflow{} code and integrates seamlessly with its full post-processing suite, enabling the evaluation of a broad range of electronic, optical, and transport properties. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14443 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14443v1 Announce Type: new Abstract: The large-area synthesis of high-crystalline-quality two-dimensional (2D) materials is at the core of novel material integration for semiconductor technology. This effort relies on developing fabrication and characterization techniques that can uncover the material's intrinsic properties by preserving its pristine conditions. In this article, we present an all ultra-high-vacuum cluster for the growth using molecular beam epitaxy of 2D semiconductors that are unstable under ambient conditions and optical spectroscopy using low temperature (20 K) photoluminescence and Raman scattering. The optical chamber of the setup provides micrometer scale spatial resolution and the ability to scan the entire wafer. The performance of its setup regarding spatial resolution, temperature control over a temperature range of 20-300 K using a closed-cycle cryostat and long-term preservation are demonstrated using as-grown post-transition metal monochalcogenides. Furthermore, we introduce a deconvolution-based algorithm to recover spatial information under vibration using a system-specific point-spread function. This enables in situ analysis of the structural and optoelectronic properties of as-grown materials in their pristine form, providing rich and reproducible feedback for both fundamental studies and the optimization of scalable 2D material growth toward integration in advanced devices. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2404.14932 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2404.14932v4 Announce Type: replace Abstract: We investigate the structural and electronic reconstruction associated with the commensurate charge-density-wave (CCDW) phase in bulk and monolayer 1T-TaS2 using density functional theory (DFT) and Wannier-based tight-binding modeling. Structural relaxation of a sqrt(13) x sqrt(13) supercell leads spontaneously to the formation of the Star-of-David (SoD) distortion, consistent with phonon softening of the undistorted phase. We focus on establishing a direct connection between real-space lattice distortion and momentum-space electronic reconstruction. Using Wannier interpolation, we demonstrate how the CCDW-induced Brillouin zone reduction leads to band folding, narrowing of Ta 5d bands, and reconstruction of the Fermi surface. Our analysis shows that features often interpreted as Fermi surface nesting emerge naturally from band folding associated with lattice distortion. We compare our calculated electronic structure with previously reported angle-resolved photoemission spectroscopy (ARPES) results at a qualitative level. While we do not explicitly compute electronic susceptibility or electron-phonon coupling matrix elements, the results provide a consistent microscopic framework linking lattice instability and electronic structure reconstruction in 1T-TaS2. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15213 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15213v1 Announce Type: cross Abstract: We explore the expected performance of a semiconducting spin cQED quantum processor for Multiple Hypothesis Tracking (MHT) algorithm via a quantum annealing procedure. From two different benchmarking scenarios we evaluate this type of quantum annealer on a quantum emulator in which we incorporated both dynamical coherent errors and incoherent errors. From estimate of the reset, measurement and annealing time of the processor, we find that cQED-spin processors could reach a total run time of around 50 ms. This makes this technology promising for potential real time application such as radar tracking. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15091 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15091v1 Announce Type: cross Abstract: Collective spin systems -- spin ensembles coupled to a common reservoir and effectively described by a single macrospin -- play an important role in both atomic and solid-state physics. Their intrinsic nonlinearity gives rise to multiple long-lived metastable states that ultimately relax to a unique most probable state. This dominant state can change with a control parameter, leading to first-order phase transitions. We develop a real-time instanton approach based on quantum quasiprobability dynamics that captures the stationary state in the large-spin limit and the asymptotic scaling of relaxation rates. We further show that these features are not accurately described by the previously applied semiclassical Wigner approach due to its neglect of non-Gaussian fluctuations. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15019 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15019v1 Announce Type: cross Abstract: Magnetic skyrmions are emerging as promising candidates for next-generation information technologies, while the realization of scalable skyrmion lattices with tailored configurations is essential for advancing fundamental skyrmion physics and developing future applications. Here we achieved the controllable generation and regulation of a large-area, highly oriented skyrmion track array (STA) in ferromagnetic Fe3GaTe2 using a vector magnetic field manipulation technique. The orientation and ordering of STA, along with the types and density of skyrmions, are precisely controlled by modulating parameters during the manipulation. The critical roles of in-plane magnetic fields and Dzyaloshinskii-Moriya interaction in STA generation is further confirmed by micromagnetic simulation. Our findings develop a strategy for engineering large-area and highly-oriented skyrmion configurations, offering a new pathway for the future application of next-generation spintronic and information technologies. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14917 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14917v1 Announce Type: cross Abstract: Active colloidal microparticles require reliable actuation to sustain directed motion. Light-based propulsion is particularly attractive as it provides persistent energy supply and enables direct spatiotemporal control. Here, we introduce 3D-printable particles with symmetry-broken refractive index profiles (SBRIP particles) that achieve propulsion through direct momentum transfer from asymmetric light refraction. Internal refractive-index gradients provide optical symmetry breaking independent of external shape, fundamentally decoupling propulsion from particle geometry. Geometrically symmetry-broken particles with a homogeneous refractive index are another special case, where propulsion originates from refractive contrast at the boundary instead of within the particle. Unlike conventional systems relying on absorption or reflection, this transparency-based mechanism minimizes heating and mitigates shadowing in bulk suspensions. We present a theoretical framework for refractive propulsion as well as numerical simulations of the SBRIP particles using raytracing and the finite volume method. This is complemented by experiments, validating the momentum transfer mechanism using particles with geometric symmetry breaking. The high transparency of our particles ensures deep light penetration, enabling the realization of volumetric active matter. This opens pathways toward adaptive nonlinear optical materials where light-driven particle reorganization modulates the local refractive index, establishing a dynamic feedback loop between the optical field and the material structure. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14538 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14538v1 Announce Type: cross Abstract: The spontaneous breaking of symmetries is a cornerstone of physics, defining the phases of matter from the cosmological scale to the quantum realm. In condensed matter, electronic orders are classified by their behavior under fundamental symmetries like spatial inversion (parity). While even-parity orders, such as conventional superconductivity and charge density waves, are ubiquitous, their odd-parity counterparts--predicted to host exotic phenomena such as gapless quasiparticle excitations and novel collective modes--are comparatively elusive states of quantum matter. Here, using high-resolution scanning tunneling microscopy and angle-resolved photoemission spectroscopy on the kagome metal CsV$_3$Sb$_5$, we report the discovery of an inversion symmetry-breaking $f$-wave charge bond order. We show that this phase, which preserves translation symmetry, is stabilized by the spontaneous opening of a spectral gap at a previously overlooked Dirac point, providing a textbook condensed-matter realization of the Gross-Neveu model for dynamical mass generation and parity breaking. Intriguingly, this $f$-wave order is itself a intervening phase, vanishing abruptly below a temperature of 10\,K and pointing to a subsequent transition into a `hidden' electronic state that is invisible to local STM probes. Our findings establish odd-parity charge order as a novel phase of matter, here, embedded within the intricate hierarchy of correlated electronic orders on the kagome lattice. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14533 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14533v1 Announce Type: cross Abstract: The single orbital, one-dimensional, Hatano-Nelson Hamiltonian provides deep insight into the physics of non-Hermiticity, resulting from asymmetric left/right hopping, and its connections to localization. In the absence of disorder, its single particle eigenvalues $E_{\alpha}$ lie on an ellipse in the complex plane whose extent in the imaginary direction is controlled by the degree of asymmetry. When randomness is introduced, two sets of real eigenvalues emerge at the extremes of the largest and smallest real part of $E_{\alpha}$. These real eigenvalues are associated with localized eigenvectors. For spinless fermions, increasing near-neighbor interactions first cause a transition to a charge density wave phase, and ultimately, on finite lattices, a collapse of all eigenvalues to the real axis. In this paper, we explore the presence of real eigenvalues in the interacting, two-particle sector for the spinful case (Hubbard model) in a two-chain (two-band) geometry with a Hermitian interchain hopping. Our key results are to obtain the ``phase" diagrams for the existence of a purely real spectrum, as a function of the interaction strength, degree of non-Hermiticity, and interchain hopping. We study the sensitivity to boundary conditions of the spectral properties of our two-chain model with winding number analysis and explore the relationship between PBC doublon states and OBC skin modes. To address the question of stability in such non-equilibrium systems, we solve the dynamics at low filling according to Lindbladian evolution and find that the non-Hermitian description is able to qualitatively describe such systems. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14382 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14382v1 Announce Type: cross Abstract: The Lindblad (GKLS) master equation, which represents the mathematical form for the general evolution of a density matrix, is a versatile and widely-used tool in open quantum systems. In contrast with the typical approach of imposing additional conditions on the system, such as weak coupling or energy conservation, we explore the structure of the equation with no assumptions. We demonstrate that general quantum dynamics can be expressed through a combination of free evolution, exchanges of some physical quantities (generalised charges), not necessarily commuting with the Hamiltonian, between the system and the bath, and pure dephasing. This result comprises a novel perspective on quantum master equations, employing physical processes as elemental parts. We use it to explore the dynamics and stationary states of a two-level system and show that strong coupling, particle exchange, and non-Abelian effects all share the same physical origin. Moreover, we demonstrate that the generalised Gibbs state for all three cases contains a non-commutation term, which has not been previously considered. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14378 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14378v1 Announce Type: cross Abstract: The Klein Paradox -- the anomalous scattering of relativistic fermions off a high potential step -- signals the limit of the single-particle interpretation of the Dirac equation. While Quantum Field Theory (QFT) resolves this via pair production, the microscopic mechanism is often obscured by abstract formalism. In this work, we investigate this phenomenon through the framework of Analog Gravity and Condensed Matter Physics. We utilize a hydrodynamic model wherein a relativistic particle is treated as a localized elastic excitation (defect) within a continuous linear medium. We demonstrate that when the external stress (potential) exceeds the medium's binding energy threshold ($V > 2mc^2$), the system undergoes a mechanical instability analogous to dielectric breakdown. This instability naturally generates modes with inverted topological winding, which we identify as antiparticles. By solving the boundary conditions for this elastic system, we reproduce the transmission coefficients of Hansen and Ravndal and recover the Schwinger limit for pair production rates. This approach provides a clear pedagogical model based on continuum mechanics to visualize vacuum decay processes, suggesting that the "paradox" is simply the elastic response of a medium under supercritical stress. This mechanical analogy serves as a pedagogical bridge for graduate students in condensed matter physics and advanced materials science, offering a concrete visualization of vacuum instability that complements standard abstract QFT derivations. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15276 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15276v1 Announce Type: new Abstract: Over the last decade, the development of Josephson devices based on van der Waals (vdW) materials has advanced rapidly, representing a paradigm shift driven by the advent of 2D materials. The diverse vdW materials library, combined with advanced fabrication techniques, enables the integration of materials with vastly disparate properties for scientific exploration. The vdW Josephson junctions (JJs) offer a unique route to explore novel functionalities and associated physics that remain inaccessible in conventional JJs, which have reached an industrial level in terms of fabrication. Beyond material diversity, vdW crystalline materials offer fundamental new control over device symmetries, enabling the realization of Hamiltonians unique to 2D systems. Furthermore, the long relaxation times of myriad excitations in 2D heterostructures open possibilities for creating exquisite quantum sensors, with the 2D material itself acting as an efficient bus for transmitting excitations to the active sensing element. This creative explosion in vdW-based superconducting electronics is rapidly growing, and our review highlights the resulting devices and physics. The confluence of vdW JJs with twistronics and topology has the potential to redefine superconducting quantum technology, enabling applications from quantum computation to ultra-sensitive hybrid sensors. While opportunities abound with vdW JJs, the challenge of scalability must be surmounted for translation into real-world devices. This review synthesizes current developments and offers a roadmap for researchers navigating this burgeoning field. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15133 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15133v1 Announce Type: new Abstract: We propose a Hanbury Brown-Twiss interferometer for a $\nu=2/5$ fractional quantum Hall edge system, in which quasiparticles tunnel between two co-propagating edge modes. In contrast to the previously studied anyonic Fabry-P\'{e}rot and Mach-Zehnder interferometers, the proposed setup relies purely on two-particle interference rather than single-particle interference. In the weak-tunneling regime, we employ a bosonized edge theory together with Keldysh perturbation theory to evaluate the cross-correlation of the tunneling currents. In the large-device limit, we obtain an analytic expression for the flux-dependent noise, whose structure closely resembles that of an electronic HBT interferometer, but with the electron charge replaced by the fractional charge $e^{\star}=e/3$ and with scaling dimensions characteristic of the fractional edge modes. In this limit, the explicit anyonic exchange phases cancel, whereas when the device size becomes comparable to the thermal length, the cross-correlation may recover a more explicit dependence on the anyonic statistical angle. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15062 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15062v1 Announce Type: new Abstract: Hydrodynamic electron transport, namely, the electric behaviors in solid materials at the macroscopic level are similar to the fluid hydrodynamics when the momentum-conserving electron-electron scattering plays the leading role, has got much attention in the past ten years. However, most of previous studies mainly focus on the electric properties. In this work, the thermal behaviors of hydrodynamic electron transport in a homogeneous 2D Corbino disk geometry is studied by the electron Boltzmann transport equation (eBTE) coupled with the Poisson equation under the magnetic field perpendicular to disk plane. Results show that in the electron hydrodynamic regime, the heat flux deflection phenomenon appears under the radial electric field or temperature gradient, namely, the heat flux no longer flows only along the radial direction and there is heat flux in the tangential direction of the radius. Heat flux deflection phenomenon is suppressed by momentum-relaxing scattering process and promoted by momentum-conserving scattering process. When an electric potential gradient or temperature gradient in the same direction is applied separately, the direction of heat flux is reversed in the electron hydrodynamic regime. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.15036 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.15036v1 Announce Type: new Abstract: Quantum dot based platforms offer a promising route towards realizing the Kitaev chain Hamiltonian hosting Majorana bound states (MBSs). Poor man's MBSs arise in a two-site Kitaev chain when the parameters of the system are fine-tuned to the sweet spot. Based on our previous work [Phys. Rev. B 111, 155410 (2025)], we consider a microscopic model for the Kitaev chain based on quantum dots with proximity effect embedded in a photonic cavity. We find that the photon coupling in the microscopic model yields an effective Hamiltonian where the cavity affects the pairing term. However, we demonstrate that even in this case, it is possible to screen particle interactions and reach the sweet spot condition for the emergence of the poor man's MBSs. In particular, we find that attractive particle interactions can be canceled for the cavity prepared in the zero-photon state, while repulsive ones can be screened with a cavity prepared in the one-photon state. Furthermore, in case of a large number of photons in the cavity, we find that the hopping amplitudes are suppressed resulting in a degenerate spectrum. This motivates the use of quantum light for engineering poor man's MBSs with cavity embedding. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14817 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14817v1 Announce Type: new Abstract: Magnetic tunnel junction (MTJ) is the key component to enable information access and increasing number of MTJs is integrated to develop high-density spintronic devices. However, continuous miniaturization of the conventional MTJs is hindered by stray magnetic fields. Altermagnets, combining the advantages of both ferromagnets and antiferromagnets, provide a promising alternative to fabricate versatile MTJs with exotic properties, such as giant spin splitting, high intrinsic frequency, and absence of stray fields. Inspired by the altermagnetic metal candidate KV2Se2O reported recently, we design an altermagnetic tunnel junction (AMTJ) based on KV2Se2O/SrTiO3/KV2Se2O. Using density functional theory combined with non-equilibrium Green's function, we investigate the layer-dependent quantum transport properties and the tunneling magnetoresistance (TMR) of such AMTJ device. Our calculated results reveal that the transmission of the AMTJ device exhibits a pronounced oscillation behavior dependent on the number of layers of the SrTiO3 semiconductor, which is attributed to the interface configuration determined by parity of the layer number. In odd-layer devices, the electron-rich O-Se interface exhibits a smooth effective potential and enables transverse momentum (k||) transport channels, leading to enhanced transmission. In contrast, in even-layer devices, the Ti-Se interface presents a steeper effective potential, impeding quantum transport through transverse momentum (k||) channels. A giant TMR of 4.6*10^7% is predicted to be realized by using a 4-layer SrTiO3. Our findings not only provide physical understanding relevant to the quantum transport in AMTJs, but also unveil that the barrier interface engineering is a strategy to tune the magnetoelectric performance. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14780 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14780v1 Announce Type: new Abstract: While significant advancements have been made in weak magnetic field detection, conventional high-sensitivity techniques are often limited by requirements for cryogenic operation or bulky setups. In this work, we develop a sensitive alternating magnetic field sensor based on a coupled system of an active microwave cavity and yttrium iron garnet (YIG), with the components implemented on printed circuit boards (PCBs). By introducing electrically tunable gain to compensate for cavity losses, we substantially improve both the quality factor and the signal intensity. Under the coupled system, Floquet modulation is induced by the alternating magnetic field, allowing for weak field detection by driving a specific hybrid mode and measuring the resulting Floquet sidebands. This miniaturized device operates at room temperature, achieving a detection limit of 121 pT/\sqrt{Hz}. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14777 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14777v1 Announce Type: new Abstract: Nanofluidic devices prompts unconventional ion transports appealing to energy and information technologies, thanks to the susceptibility of confined electric double layers (EDL) to various external physical fields. Although experimental studies advance rapidly, the rationalization of field-tunable nanofluidic transports has not reached a formalized and unified level. Here we formally reformulate the Poisson-Boltzmann theory and reveal distinct EDL regimes on the parameter space. Based on the regime classification, we establish a formal framework for the tunable nanofluidic transport, which reproduces the observed conductivity-concentration scaling behaviors, rationalizes the ionic transistors with reconfigurable polarities, and predicts two fundamental thermodynamic limits for electrostatic modulation (60 mV/dec and 120 mV/dec). Being accurate, generalizable and extensible, this framework can account for a wide range of ion transports in confined spaces. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14770 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14770v1 Announce Type: new Abstract: Phononic silicon structures have emerged as an integrable and scalable nanosystem for tailoring thermal transport. However, their widespread adoption has been limited by their complex fabrication pathways. Alongside, the reliable characterization of thermal properties in suspended nanostructured films remains challenging, as thermal contact resistances often hinder the accuracy of measurements. In this work, we demonstrate a clear and controllable reduction of thermal conductivity in nanopatterned silicon membranes. A block copolymer self-assembly approach is employed to fabricate nanoholed silicon films with a pitch of 63 nm and hole diameters of 35 nm. Additionally, we introduce an extension of the three-probe technique that enables robust, quantitative, and spatially resolved thermal conductivity measurements in complex thin-film systems, accounting for thermal contact artifacts. The method is validated through measurements on unpatterned 40 nm-thick silicon thin films between 30 and 350 K, yielding a room-temperature thermal conductivity of 46.5 W/m.K. Finally, we further show that controlled etching of the nanoholes provides a powerful means to tune thermal transport in the overall studied temperature range, establishing hole etch depth control as an effective parameter in phononic silicon. Specifically, a fivefold reduction in thermal conductivity is achieved, reaching 7.3 W/m.K for fully etched-through membranes at room temperature. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14737 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14737v1 Announce Type: new Abstract: Advances in nanotechnology now allow the creation of artificial atoms - engineered structures whose electronic states closely mimic those of real atoms. Understanding how these artificial atoms interact and bond is key to designing new materials with tailored electronic properties. Here, we use scanning tunnelling microscopy to visualise the bound states of nanostructures patterned in a two-dimensional molecular film featuring a parabolic band with multiple partial energy gaps. The lowest-energy states split off from the bottom of the band and resemble the familiar $s$ and $p$ orbitals of natural atoms, even bonding in the same way. Yet, artificial atoms go beyond this analogy: the gapped two-dimensional vacuum in which they reside gives rise to entirely new orbitals with no counterparts in real atoms. These quasi-one-dimensional localised states enrich the orbital vocabulary of chemistry, adding a new class of orbitals that are predominantly shaped by the surrounding electronic vacuum. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14665 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14665v1 Announce Type: new Abstract: Utilization of Faraday rotation (FR) properties of topological materials offers a promising route toward novel magneto-optical devices. We systematically investigated the effect of Rashba spin-orbit coupling (SOC) on FR spectra in an extended Haldane model, which incorporates Rashba SOC and exchange splitting into the original spinless Haldane framework. Using the Kubo formalism, we calculated the FR spectra across the model's rich topological phase diagram. We found that in the Chern number C=2 region, in the absence of exchange splitting, the FR angle can exceed 4$^\circ$ and its peak position is tunable by the Rashba SOC. In contrast, with the inclusion of exchange splitting, a nearly flat FR profile emerges over a broad frequency range, and the FR peak values increase monotonically with the Rashba SOC strength. The Rashba SOC opens additional transition channels, whose net contribution constructively enhances the FR peak. Furthermore, we derived a low-energy effective Hamiltonian expanded up to quadratic terms, the results of which are in good agreement with tight-binding model calculations, thereby validating our numerical results. Our findings suggest that magneto-optical device characteristics can be designed and optimized through Rashba SOC engineering. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14521 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14521v1 Announce Type: new Abstract: We theoretically study the direct and inverse spin Hall effects in a superconductor-normal metal-superconductor junction induced by a spin-orbit interaction that is invariant under spatial inversion. We show that a supercurrent induces a spin Hall effect, leading to a static spin accumulation with opposite polarizations at the two edges, analogous to that in normal conductors. For the inverse effect, we consider a spatially inhomogeneous static magnetic field and show that it induces an anomalous phase shift, which, in the presence of higher harmonics, results in a diode effect. Unlike Rashba systems, the present mechanism does not require broken structural inversion symmetry. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2601.01309 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2601.01309v3 Announce Type: replace-cross Abstract: Disorder in quantum many-body systems can drive transitions between ergodic and non-ergodic phases, yet the nature--and even the existence--of these transitions remains intensely debated. Using a two-dimensional array of superconducting qubits, we study an interacting spin model at finite temperature in a disordered landscape, tracking dynamics both in real space and in Hilbert space. Over a broad disorder range, we observe an intermediate non-ergodic regime with glass-like characteristics: physical observables become broadly distributed and some, but not all, degrees of freedom are effectively frozen. The Hilbert-space return probability shows slow power-law decay, consistent with finite-temperature quantum glassiness. In the same regime, we detect the onset of a finite Edwards-Anderson order parameter and the disappearance of spin diffusion. By contrast, at lower disorder, spin transport persists with a nonzero diffusion coefficient. Our results show that there is a transition out of the ergodic phase in two-dimensional systems. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2507.08930 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2507.08930v2 Announce Type: replace-cross Abstract: We present a formalism that allows for the direct manipulation and optimization of subspaces, circumventing the need to optimize individual states when using subspace methods. Using the determinant state mapping, we can naturally extend notions such as distance and energy to subspaces, as well as Monte Carlo estimators, recovering the excited states estimation method proposed by Pfau et al. As a practical application, we then introduce Bridge, a method that improves the performance of variational dynamics by extracting linear combinations of variational time-evolved states. We find that Bridge is both computationally inexpensive and capable of significantly mitigating the errors that arise from discretizing the dynamics, and can thus be systematically used as a post-processing tool for variational dynamics. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2510.24704 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2510.24704v2 Announce Type: replace Abstract: We investigate long-range resonances in quasiperiodic many-body localized (MBL) systems. Focusing on the Heisenberg chain in a deterministic Aubry-Andr\'{e} potential, we complement standard diagnostics by analyzing the structure of long-distance pairwise correlations at high energy. Contrary to the expectation that the ergodic-MBL transition in quasiperiodic systems should be sharper due to the absence of Griffiths regions, we uncover a broad unconventional regime at strong quasiperiodic potential, characterized by fat-tailed distributions of longitudinal correlations at long distance. This reveals the presence of atypical eigenstates with strong long-range correlations in a regime where standard diagnostics indicate stable MBL. We further identify these anomalous eigenstates as quasi-degenerate pairs of resonant cat states, which exhibit entanglement at long distance. These findings advance the understanding of quasiperiodic MBL and identify density-correlation measurements in ultracold atomic systems as a probe of long-range resonances. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2505.20954 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2505.20954v4 Announce Type: replace Abstract: We define and study a statistical mechanics ensemble that characterizes connected solutions in constraint satisfaction problems (CSPs). Built around a well-known local entropy bias, it allows us to better identify hardness transitions in problems where the energy landscape is dominated by isolated solutions. We apply this new device to the symmetric binary perceptron model (SBP), and study how its manifold of connected solutions behaves. We choose this particular problem because, while its typical solutions are isolated, it can be solved using local algorithms for a certain range of constraint density $\alpha$ and threshold $\kappa$. With this new ensemble, we unveil the presence of a cluster composed of delocalized connected solutions. In particular, we demonstrate its stability until a critical threshold $\kappa^{\rm no-mem}_{\rm loc.\, stab.}$ (dependent on $\alpha$). This transition appears as paths of solutions shatter, a phenomenon that more conventional statistical mechanics approaches fail to grasp. Finally, we compared our predictions to simulations. For this, we used a modified Monte-Carlo algorithm, designed specifically to target these delocalized solutions. We obtained, as predicted, that the algorithm finds solutions until $\kappa\approx\kappa^{\rm no-mem}_{\rm loc.\, stab.}$. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2502.10918 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2502.10918v3 Announce Type: replace Abstract: Glasses are traditionally characterized by their rugged landscape of disordered low-energy states and their slow relaxation towards thermodynamic equilibrium. Far from equilibrium, dynamical forms of glassy behavior with anomalous algebraic relaxation have also been noted, for example, in networks of coupled oscillators. Due to their disordered and high-dimensional nature, such systems have been difficult to study theoretically, but data-driven methods are emerging as a promising alternative that may aid in their analysis. Here, we characterize glassy dynamics using the dynamic mode decomposition, a data-driven spectral computation that approximates the Koopman spectrum. We show that the gap between oscillatory and decaying modes in the Koopman spectrum vanishes in systems exhibiting algebraic relaxation, and thus, we propose a model-agnostic signature for robustly detecting and analyzing glassy dynamics. We demonstrate the utility of our approach through both a minimal example of a one-dimensional ODE and a high-dimensional example of coupled oscillators. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.14718 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14718v1 Announce Type: cross Abstract: This article argues that the most important significance of the AI revolution, especially the rise of large language models, lies not simply in automation, but in a fundamental change in how complex information and human know-how are carried, replicated, and shared. From this perspective, AI for Science is especially important because it may transform not only the efficiency of research, but also the structure of scientific collaboration, discovery, publishing, and evaluation. The article outlines a gradual path from AI as a research tool to AI as a scientific collaborator, and discusses how AI is likely to fundamentally reshape scientific publication. It also argues that continuous learning and diversity of ideas are essential if AI is to play a meaningful role in original scientific discovery. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.14387 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14387v1 Announce Type: cross Abstract: Recent work has emphasized a subtlety of large- $N$ limits in AdS/CFT: a sequence of pure states in the microscopic theory need not remain pure with respect to the emergent algebra of observables. We study this phenomenon for Kourkoulou-Maldacena (KM) states in the double-scaling limit of the SYK model, and show that their ensemble-averaged algebraic description depends crucially on which observables survive the limit. For fermionic operators of size $N^{1/2}$, generic operators converge to the usual chord operators of double-scaled SYK. The resulting von Neumann algebra is the standard Type II$_1$ factor, and the KM pure states at infinite temperature converge to the tracial state, so generic probes lose access to microscopic purity. We then identify a class of operators adapted to the KM state that also survives the double-scaling limit. Since the KM state may be viewed as a projection inside the tracial state, these become dressed chord creation and annihilation operators. Once included, the limiting algebra becomes Type I$_\infty$ and the limiting state becomes pure. This gives a concrete example in which adding a sufficiently state-adapted operator to the emergent algebra restores access to the purity of the underlying state. We further show that correlators of the dressed operators admit exact modified chord-diagram rules, derive analytic expressions for uncrossed $2n$-point and crossed four-point functions, analyze their finite-temperature semiclassical and Schwarzian limits, study a deformation of the chord Hamiltonian that produces bound states and extends the correspondence with JT gravity plus an EOW brane to general brane tension, and identify an emergent $U(1)$ symmetry together with its finite-$N$ violation. Finally, we discuss analogies with boundary algebras proposed for black hole interiors and closed universes, and suggest lessons from our construction for both. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.14335 Fri, 17 Apr 2026 00:00:00 -0400 arXiv:2604.14335v1 Announce Type: cross Abstract: We derive the reduced Dirac Hamiltonian on the non-rotating BTZ background and use its redshift structure to construct a gauge-covariant single-band lattice model on the constant-time BTZ cylinder. In equal-area coordinates the AdS radius $L$ fixes the local Gaussian curvature, while the horizon radius $r_h$ fixes the throat size and the strength of the near-horizon redshift. The lattice model therefore has a direct geometric interpretation and is not presented as an unshown reduction of the two-component Dirac lattice. Its angular Fourier transform yields an exact curved Harper equation with BTZ-dependent hopping amplitudes and a consistent dimensionless angular quasi-momentum. We then supplement global parameter scans with state-resolved diagnostics: spectra color-coded by mean radius, local density of states, direct flux-response versus radius correlations, and Aharonov--Bohm spectral flow and persistent current on the BTZ cycle. These results show that weaker curvature sharpens the butterfly-like fragmentation, whereas larger horizons suppress both magnetic and Aharonov--Bohm response by creating weakly dispersing near-horizon states. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.13161 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13161v1 Announce Type: new Abstract: The superconducting transition temperature $T_c$ of the two-dimensional attractive Hubbard model is computed in the vicinity of both ordinary (logarithmic) and higher-order (power-law) Van Hove singularities using determinant quantum Monte Carlo simulations. For interaction strengths $|U| \lesssim W/3$, where $W$ is the electronic bandwidth, $T_c$ is enhanced in the neighborhood of the Van Hove point, albeit more weakly than expected from weak-coupling BCS theory. Enhancing the Van Hove singularity from logarithmic to power-law yields only a minor additional enhancement of $T_c$. For $|U| \gtrsim W/3$, the maximum $T_c$ shifts away from the Van Hove point and instead occurs at a density unrelated to any features in the non-interacting density of states, consistent with a strong-coupling interpretation. We find that the maximal $T_c$ in the model is achieved at intermediate $U$ and at a density away from the Van Hove point. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2512.09994 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2512.09994v2 Announce Type: replace Abstract: Experiments show that the Weyl semimetal PtBi$_2$ hosts unconventional superconductivity in its topological surface states. Hence, the material is a candidate for intrinsic topological superconductivity. Measurements indicate nodal gaps in the center of the Fermi arcs. We derive that anisotropic electron-phonon coupling on Weyl semimetal surfaces, combined with statically screened Coulomb repulsion, is a microscopic mechanism for this nodal pairing. The dominant solution of the linearized gap equation shows nodal gaps when the surface state bandwidth is comparable to the maximum phonon energy, as is the case in PtBi$_2$. We further predict that if the screening of Coulomb interaction on the surface is enhanced by Coulomb engineering, the superconducting gap becomes nodeless, and the critical temperature increases. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14022 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14022v1 Announce Type: new Abstract: The current-driven resistive transition is central to superconducting single-photon detectors, transition-edge sensors, and fluxonic devices. Depending on sample uniformity, dimensions, and heat removal, it can be driven by phase-slip events, flux-flow instabilities (FFI), or normal-domain formation. Here, we investigate the influence of two types of microstructural defects on vortex dynamics in MgB$_2$ films: columnar growth in textured films and buffer-layer roughness in single-crystal films. The current-voltage ($I$-$V$) curves measured at $T \approx 0.25 T_\mathrm{c}$ for both films exhibit multiple steps. Time-dependent Ginzburg-Landau simulations reproduce the major features of the experimental $I$-$V$ curves and suggest that the resistive transitions for both films are mediated by the formation and growth of normal domains rather than FFI. The single-crystal film with buffer-layer roughness exhibits superconductivity breakdown at higher currents and pinning activation energies approximately twice those of the textured film, along with more pronounced multi-step features in the $I$-$V$ curves. These features are attributed to the combination of stronger pinning induced by lateral variations of the superconducting order parameter along the MgO buffer layer and its lower thermal boundary resistance. Our results show that both the film microstructure and the film-buffer interface are critical for the resistive transition, offering insights for superconducting devices requiring controlled dissipation at high transport currents. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2601.20189 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2601.20189v2 Announce Type: replace Abstract: Several ground state properties of the square-lattice $S=1/2$ Heisenberg antiferromagnet are computed (the energy, order parameter, spin stiffness, spinwave velocity, long-wavelength susceptibility, and staggered susceptibility) using extensive quantum Monte Carlo simulations with the stochastic series expansion method. Moderately sized lattices are studied at temperatures $T$ sufficiently low to realize the $T \to 0$ limit. Results for periodic $L\times L$ lattices with $L \in [6,96]$ are tabulated versus $L$ and extrapolations to infinite system size are carried out. The extrapolated ground state energy density is $e_0=-0.669441857(7)$, which represents an improvement in precision of three orders of magnitude over the previously best result. The leading and subleading finite-size corrections to $e_0$ are in full quantitative agreement with predictions from chiral perturbation theory, thus further supporting the soundness of both the extrapolations and the theory. The extrapolated sublattice magnetization is $m_s=0.307447(2)$, which agrees well with previous estimates but with a much smaller statistical error. The coefficient of the linear in $L^{-1}$ correction to $m^2_s$ agrees with the value from chiral perturbation theory and the presence of a factor $\ln^\gamma(L)$ in the second-order correction is also confirmed, with the previously not known value of the exponent being $\gamma = 0.82(4)$. The finite-size corrections to the staggered susceptibility point to logarithmic corrections also in this quantity. To facilitate benchmarking of methods for which periodic boundary conditions are challenging, results for systems with open and cylindrical boundaries are also listed and their spatially inhomogeneous order parameters are analyzed. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2512.13786 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2512.13786v2 Announce Type: replace Abstract: Dynamical control of quantum matter is a challenging, yet promising direction for probing strongly correlated states. Motivated by recent experiments in twisted MoTe$_2$ that demonstrated optical control of magnetization, we propose a protocol for probing magnetization dynamics in flat-band ferromagnets. We investigate the nucleation and dynamical growth of magnetic bubbles prepared on top of a false vaccum in both itinerant ferromagnets and spin-polarized Chern insulators. For ferromagnetic metals, we emphasize the crucial role of a non-trivial quantum geometry in the magnetization dynamics, which in turn also provides a probe for the quantum metric. Furthermore, for quantum Hall ferromagnets, we show how properties of chiral edge modes localized at domain-wall boundaries can be dynamically accessed. Our work demonstrates the potential for nonequilibrium protocols to control and probe strongly correlated phases, with particular relevance for twisted MoTe$_2$ and graphene-based flat-band ferromagnets. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.25994 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2510.25994v2 Announce Type: replace Abstract: We generalize the Hyperbolic Fracton Model from the $\{5,4\}$ tessellation to generic tessellations, and investigate its core properties: subsystem symmetries, fracton mobility, and holographic correspondence. While the model on the original tessellation has features reminiscent of the flat-space lattice cases, the generalized tessellations exhibit a far richer and more intricate structure. The ground-state degeneracy and subsystem symmetries are generated recursively layer-by-layer, through the inflation rule, but without a simple, uniform pattern. The fracton excitations follow exponential-in-distance and algebraic-in-lattice-size growing patterns when moving outward, and depend sensitively to the tessellation geometry, differing qualitatively from both type-I or type-II fracton model on flat lattices. Despite this increased complexity, the hallmark holographic features -- subregion duality via Rindler reconstruction, the Ryu-Takayanagi formula for mutual information, and effective black hole entropy scaling with horizon area -- remain valid. These results demonstrate that the holographic correspondence in fracton models persists in generic tessellations, and provide a natural platform to explore more intricate subsystem symmetries and fracton physics. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2509.20337 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.20337v2 Announce Type: replace Abstract: As a consequence of their spin-orbit entangled ground state, many $5d^{5}$ iridate materials display a peculiar double peak structure in optical transport quantities, such as absorption and conductivity. Their common interpretation is based on the presence of Hubbard subbands in the half-filled $j_{\mathrm{eff}}=1/2$ manifold. Herein, we challenge this picture, proposing a scenario based on the presence of spin-polaron (SP) quasiparticles, and assigning a dominant SP character to the first peak. We illustrate it by taking the materials Ba$_2$IrO$_4$ and Sr$_2$IrO$_4$ as paradigmatic examples, which we investigate within the dynamical mean-field theory and the self-consistent Born approximation. Both theories reproduce nontrivial features revealed by angle-resolved photoemission spectroscopy and optical transport measurements, supporting our interpretation. In the case of Sr$_2$IrO$_4$, we show how the SP scenario survives in the low-doped regime. Similar optical transport fingerprints are expected to be found in the wider class of $5d^5$ iridates and more generally in strongly correlated antiferromagnetic regimes, such as those found in cuprates. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2509.19764 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.19764v5 Announce Type: replace Abstract: Moir\'e superlattices host a rich variety of correlated topological states, including interaction-driven integer and fractional Chern insulators. A common approach to study interacting ground states at integer fillings is the Hartree-Fock mean-field method. However, this method neglects dynamical correlations, which often leads to an overestimation of spontaneous symmetry breaking and fails to provide quantitative descriptions of single-particle excitations. This work introduces a general many-body perturbation framework for moir\'e systems, combining all-band Hartree-Fock calculations with $GW$ quasiparticle corrections and random phase approximation (RPA) correlation energies. We apply this framework to hexagonal boron nitride aligned rhombohedral pentalayer graphene and magic-angle twisted bilayer graphene (MATBG). We show that incorporating RPA correlation energy and $GW$ self-energy corrections yields phase diagrams and single-particle spectra that quantitatively align with experimental measurements for both systems. Particularly, the ground state at charge neutrality of MATBG is predicted to be a nematic metal, which is stabilized over Kramers intervalley coherent insulator due to lower correlation energy. Our versatile framework provides a systematic beyond-mean-field approach applicable to generic moir\'e systems. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2504.03324 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2504.03324v3 Announce Type: replace Abstract: We demonstrate the existence of an unconventional pairing state in photodoped Mott insulators on ladder and quasi-two-dimensional geometries, characterized by quasi-long-range doublon-holon correlations that signal Mott exciton condensation. The doublon-holon pairing exhibits correlations of $d$-wave-like symmetry, reminiscent of superconducting pairing in chemically doped Mott insulators. By constructing the phase diagram, using density matrix renormalization group, we reveal that the doublon-holon pairing state in the photodoped ladder emerges between the spin-singlet, charge-density-wave, and $\eta$-pairing phases. Our study suggests that the interplay of charge, spin, and $\eta$-spin degrees of freedom can give rise to exotic quantum many-body states in photodoped Mott insulators. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2502.04814 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2502.04814v2 Announce Type: replace Abstract: CeTe$_3$ is a 2--dimensional (2D) Van der Waals (VdW) material with incommensurate charge density waves (CDW), extremely high transition temperature ($T_{CDW}$) and a large momentum--dependent CDW gap that leaves a significant portion of the Fermi surface intact. It is also considered to be a weak Kondo system, a property unexpected for a material with incommensurate CDW, where each atomic site is slightly different. Here, we study the properties of the CDW state in several RTe$_3$ (R is rare earth) materials and examine the hybridization of itinerant states with the localized Ce $4f$ multiplet in CeTe$_3$ by using angle resolved photoemission spectroscopy (ARPES). We find that the renormalization of the itinerant states originating from the hybridization with the deeper localized $4f$ states at $-260$ meV is $k-$dependent and extends to the Fermi level. As these localized states are far from the Fermi level, the observed hybridization affects the effective masses only marginally and does not lead to heavy fermions. However, since the same renormalizing mechanism normally leads to the heavy fermion physics when the localized $4f$ states are near the Fermi level, our observation of its strong $k-$dependence suggests that this could be the reason for discrepancy between the heavy masses in specific heat and light ones in Shubnikov de Haas oscillations, often observed in heavy fermions. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14115 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14115v1 Announce Type: cross Abstract: In this paper, we develop a class of antisymmetrized geminal power configuration interaction (AGP-CI) wave functions that extend the AGP framework by incorporating inter-geminal correlations through a CI expansion. To make these wavefunctions computationally tractable, we evaluate them by rewriting the AGP-CI ansatz as a linear combination of AGPs (LC-AGP), for which overlaps and Hamiltonian matrix elements can be computed with standard AGP machinery. Motivated by border-rank decompositions, we further reorganize this ansatz into a compact linear combination of AGPs depending on a small deformation parameter $\tau$, which controls how closely the truncated expansion approximates the full AGP-CI state. Benchmark applications to the Hubbard model and to the small molecules H$_2$O and N$_2$ demonstrate that the proposed wavefunctions achieve consistently high accuracy and outperform the LC-AGP, particularly for systems with more electrons and in strongly correlated regimes. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14045 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14045v1 Announce Type: cross Abstract: The supercurrent diode effect (SDE), characterized by unequal critical currents in opposite directions, has been observed with or without magnetic fields, yet mechanisms enabling zero-field SDE without explicit symmetry breaking remain underexplored. Here we investigate a Josephson junction with strong electron-electron interaction modeled by a Hubbard $U$ term and an odd number of electrons. We find that strong correlations induce spontaneous breaking of time-reversal and mirror symmetries, forming a $\varphi$-junction with degenerate energy minima at $\pm\varphi$, resulting in zero-field Josephson diode effect (JDE) without magnetic order. Spin-orbit coupling breaks SU(2) symmetry but does not determine diode polarity, contrasting with magneto-chiral mechanisms. We further show that applying a tiny Zeeman field enables controllable JDE with sizable efficiency due to the enhancement by the strong magnetic correlation, and the JDE strength peaks when the field induces a level-crossing transition. These findings establish strong electron correlation as a distinct mechanism for nonreciprocal superconducting transport, broadening the understanding of SDE origins. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14146 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14146v1 Announce Type: new Abstract: Investigating the interplay among topology and electron-electron interactions is an intriguing research quest which has recently gathered steam across the community of condensed-matter physics. In the present work, we study the fate of a three-dimensional Berry-dipole semimetal, lying at the topological quantum critical point separating a Hopf insulator from a trivial insulator, in the presence of long-range Coulomb interactions. Utilizing large-$N_f$ analysis at three spatial dimensions and an $\epsilon$-expansion within the renormalization-group scheme, we uncover the emergence of a spatially \textit{anisotropic} non-Fermi liquid with enhanced Berry-dipole moment. We further derive the corresponding scaling relations of certain physical observables as functions of the probed energy and temperature scale, and we provide a simple observational criterion for distinguishing the onset of the topological anisotropic non-Fermi liquid from a Berry-dipole semimetal. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14012 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14012v1 Announce Type: new Abstract: The novel kagome family RTi3Bi4 (R: rare-earth) offers a unique platform for exploring distinctive physical phenomena such as anisotropy, spin density wave, and anomalous Hall effect. In particular, the magnetic frustration and behavior of magnetic anisotropy in antiferromagnetic (AFM) kagome materials are of great interest for the fundamental studies and hold promise for next-generation device applications. Here, we report a tunable bifurcation of magnetic anisotropic and bi-oriented AFM order observed in the quasi-1D kagome antiferromagnet GdTi3Bi4. The magnetic domain evolutions during two plateau transition processes are directly visualized, unveiling a pronounced in-plane anisotropy along the a-axis. Temperature-dependent characterization reveals a bifurcation transition of anisotropy at approximately 2 K, where the a-axis anisotropy splits into two special orientations, revealing a hidden bi-oriented in-plane AFM order deviating from the high-symmetry direction by 7 degree. More intriguingly, the characteristics of the bifurcated anisotropy are clearly illustrated through vector magnetic field modulation, revealing three distinct in-plane domain phases in the transverse magnetic field phase diagram. Our results not only provide valuable insights into the tunable bifurcation of magnetic anisotropic in GdTi3Bi4, but also pave a novel pathway for AFM spintronics development. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14002 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14002v1 Announce Type: new Abstract: Charge density waves (CDWs) are a widespread collective electronic order in quantum materials, furnishing key insights into symmetry breaking and competing phases. However, their dynamic control with external fields remains a pivotal challenge. Here, we report deterministic and hysteretic switching of unidirectional CDW orientation via in-plane magnetic field rotation in magnetic kagome metal GdTi3Bi4. Atomically resolved spectroscopy shows two types of 3a0*1a0 CDW domains, Q1 and Q2 oriented 60 degree apart along two distinct crystallographic directions and separated by atomically sharp domain walls. Rotating the magnetic field drives reversible transitions between these CDW configurations, exhibiting a robust C2-symmetric phase diagram with pronounced hysteresis. This hysteretic switching is mediated by a field-dependent reorientation of underlying antiferromagnetic spins, revealing a tunable energy landscape with stable and metastable states and modulates the electronic charge order via spin-lattice coupling. Our findings not only demonstrate the switching of CDW configurations by in-plane magnetic field but also reveal the mechanism of coupling between CDW and magnetic fields, offering new insights into CDW manipulation and versatile platform for developing a spin-mediated multistate spin-charge coupling memory and programmable quantum devices. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13958 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13958v1 Announce Type: new Abstract: Many-body effects in condensed matter yield novel quantum states when the electronic density of states is enhanced. A vivid example is flat bands, which suppress kinetic energy and let interactions dominate, when they are filled with an integer number of electrons in moire systems. Yet flat bands and commensurate fillings are not the only conditions for correlated phenomena. Situations may occur where the band structure develops locally enhanced density of states, leading to strong correlations even at non-integer fillings, although such cases often yield pseudogaps that make detection elusive. Here we demonstrate that small-angle twisted monolayer-bilayer graphene combines moire-induced global flat band and additional local band flattening. Their coexistence allows direct comparison of correlated effects. The global route stabilizes commensurate states, while the local mechanism produces nearly flat bands, lifting degeneracy and generating symmetry breaking at non-integer fillings, yet without opening a global gap. Because there is no global gapped signature, the system remains metallic, but the effect reveals itself in anomalous Hall responses, signaling time-reversal symmetry breaking and valley polarization. Our results demonstrate dual-flatness as a guiding principle, extending moire physics beyond commensurate fillings and identifying topological transport as a probe of gapless correlated metals. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13864 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13864v1 Announce Type: new Abstract: Structural disorder in the magnetically frustrated pyrochlore system leads to intriguing magnetic states. We present the thermodynamic behavior and short range magnetic correlations in Tb$_{2}$Zr$_{2}$O$_{7}$ and Tb$_{2}$Zr$_{1.5}$Ti$_{0.5}$O$_{7}$ compounds. The parent compound Tb$_{2}$Zr$_{2}$O$_{7}$ has defect fluorite structure, which evolves toward the pyrochlore phase on Ti doping at Zr site. There is no long range magnetic order down to 0.4 K, and a magnetic field dependent spin freezing evolves below 1.25 K and 1.05 K for the parent and doped compounds, respectively. The ac susceptibility measurements indicate slow spin relaxation process below 20 K in these compounds. Inelastic neutron scattering reveals broad diffuse scattering, indicative of short range correlations at low temperature, owing to local structural distortions and persistent spin fluctuations. These results suggest a correlated, disorder influenced magnetic state in Tb$_{2}$Zr$_{2}$O$_{7}$, Tb$_{2}$Zr$_{1.5}$Ti$_{0.5}$O$_{7}$ compounds. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13751 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13751v1 Announce Type: new Abstract: On the textbook example of an isolated antiferromagnetic Heisenberg dimer, we demonstrate that the magnetic form factor and the magnetic electron density distribution can be extracted from the momentum-dependence of the inelastic neutron scattering (INS) intensity of a magnetic excitation. We measure the three-dimensional (3D) magnetic structure factor of the singlet-to-triplet excitation in Cu(II) acetate monohydrate with INS. Using a minimal parametrization of the magnetic electron density, we deduce the real-space density of the spin-entangled electrons and the transfer of magnetic electron density between metal and ligand atoms from the experimental data. Density functional theory (DFT) calculations reproduce the measured structure factor quantitatively, providing a direct validation of DFT broken-symmetry spin densities against full 3D INS data. The quantitative agreement between experiment, parametrization, and theory establishes a robust framework for determining magnetic form factors and the magnetic electron density in a broad range of magnetic materials and demonstrates INS as a probe of the envelope of spatial electronic wavefunctions. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13651 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13651v1 Announce Type: new Abstract: We have performed detailed temperature-dependent study of optical f-f transitions of the Yb3+ ions in h-YbMnO3 by means of Fourier-transform spectroscopy. The splitting of the ground Kramers doublet as a function of temperature, D0(T), for the Yb3+ ion at 4b site was determined. The D0(T) function follows the dynamics of the manganese magnetic moment below TN = 87 K, indicating, that the ytterbium subsystem is magnetized by the magnetic field generated by an ordered manganese subsystem, which is consistent with the results of previous studies. Excitation of the upper component of the split ground doublet plays a significant role in low-temperature dynamics of the h-YbMnO3 crystal. Using the D0(T) function we calculated the temperature behavior of the of the Yb(4b) magnetic moment: it is in clear agreement with the neutron data [Phys. Rev. B 98, 134413, 2018]. The calculated contribution of Yb(4b) to heat capacity definitely explains the origin of the Schottky anomaly in the CP(T) dependence. A scenario for phase transitions in h-YbMnO3 is proposed in which the energy gain in the ytterbium system plays a key role. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13576 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13576v1 Announce Type: new Abstract: We report on new results of 9Be nuclear magnetic resonance (NMR) measurements conducted on a single crystal of the heavy fermion superconductor UBe13. Our previous 2007 study [J. Phys. Soc. Jpn. 76 204705 (2007)] determined NMR and electric field gradient (EFG) parameters that successfully reproduced the NMR spectra at low magnetic fields. However, these parameters did not accurately describe the angular dependence of the NMR spectra at high magnetic fields. To address this discrepancy, we have now performed a more comprehensive investigation, measuring the magnetic field dependence of the 9Be-NMR spectra across a field range of 0.5 T to 8 T, as well as the magnetic field angle dependence at 0.5 T and 6 T. Through detailed simulations that take into account the non-symmorphic space group of UBe13, we have determined a new set of parameters capable of reproducing the complex NMR line profiles observed at high magnetic fields. Notably, our analysis reveals the significant influence of classical dipolar fields. A comparison between the Knight shift (KS) and the classical dipolar shift provides microscopic supporting evidence for the nature of an itinerant-localized duality in UBe13. Furthermore, the magnetic field dependence of the KS exhibits anomalies around 6 T, suggesting a reconstruction of a part of the multiple Fermi surfaces in the high magnetic field region. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13553 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13553v1 Announce Type: new Abstract: As a unique kagome superconductor displaying clear signatures of strong electronic correlations, CsCr$_3$Sb$_5$ has drawn much attention. Its rich temperature-pressure phase diagram features intertwined orders including pressure-induced superconductivity and two density-wave-like phases, making it an outstanding platform to explore the complex coexistence and competition of multiple quantum orders. At around 30 K, which we designate as $T_3$, a possible anomaly manifesting as a hump in the resistivity has been observed, yet its nature remains largely unexplored due to limited supporting evidence from other probes. Here, we conducted systematic magnetotransport experiments under hydrostatic pressure to investigate the nature of this anomaly. Our results reveal an abundance of intriguing magnetotransport signatures below $T_3$, including a non-trivial temperature dependence of the Hall coefficient, multi-band characteristics, and pressure-enhanced anomalous-Hall-like effect. These signatures bear resemblance to those observed in the charge-density-wave state in the sister compound CsV$_3$Sb$_5$. These findings suggest the possibility of an additional, exotic electronic order in CsCr$_3$Sb$_5$, calling for further detailed investigations. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13093 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13093v1 Announce Type: new Abstract: Here a finite-Lieb-lattice quantum computing circuit consisting of spin-1/2 quantum bits (qubits) and triplet couplers is designed. Important gradient - quantum entanglement - is analysed. This type of design could be realised in a vast range of molecules containing multiple radicals, in which the communications among qubits are controlled by the optically driven triplets. The von Neumann entanglement entropy, reduced density matrices, and spin-spin correlations were computed using tensor-network methods by varying the magnetic anisotropy and external magnetic field. This work uncovers the rich entanglement patterns, quantum phase transitions, and tunable spin coherence in this mixed spin system, designed for molecular spin-based quantum computing. These findings have important implications for triplet-mediated molecular self-assembly quantum computing circuit, especially for the entangling gate based on molecules. This work would provide a theoretical cornerstone for the experimental realisation of scalable molecule-based quantum computing circuits. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2603.02328 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.02328v2 Announce Type: replace-cross Abstract: Local decoders provide a promising approach to real-time quantum error-correction by replacing centralized classical decoding, with significant hardware constraints, by a fully distributed architecture based on a simple, local update rule. We propose a new local decoder for Kitaev's toric code: the 2D signal-rule, that interprets odd parity stabilizer measurements as defects, attracted to each other via the exchange of binary signals. We present numerical evidence of exponential suppression of the logical error rate with system size below a threshold, under a phenomenological noise model with data and measurement errors at each iteration. The construction achieves a significantly improved threshold and optimal finite-size scaling relative to hierarchical schemes. It also provides a lightweight alternative to windowed local decoder constructions while maintaining strong performance, thus enabling a streamlined architecture for a two-dimensional local quantum memory. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2510.15766 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2510.15766v3 Announce Type: replace-cross Abstract: We introduce the subdimensional entanglement entropy (SEE), defined on subdimensional entanglement subsystems (SESs) embedded in the bulk, as an entanglement-based probe of how geometry and topology jointly shape universal properties of quantum matter. By varying the dimension, geometry, and topology of the SES, we show that the subleading term of SEE exhibits sharply distinct responses in different phases, including cluster states, $\mathbb{Z}_q$ topological orders, and fracton orders. Treating the reduced density matrix of an SES as a many-body mixed state supported on the SES manifold, we further establish a general correspondence between bulk stabilizers and mixed-state symmetries on SESs, separating them into strong and weak classes, and use it to identify strong-to-weak spontaneous symmetry breaking within SESs. Finally, for SESs with nontrivial SEE, we show that weak symmetries act as transparent patch operators of the corresponding strong symmetries. This motivates the notion of transparent composite symmetry, which remains robust under finite-depth quantum circuits that preserve SEE, and implies that each $D$-dimensional SES holographically encodes a $(D+1)$-dimensional topological order. These results establish SEE not only as a sharp probe of geometric-topological response, but also as a route from bulk pure-state entanglement to mixed-state symmetry and holography on subdimensional manifolds. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2507.01064 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2507.01064v2 Announce Type: replace-cross Abstract: Signal detection in high dimensions is a critical challenge in data science. While standard methods based on random matrix theory provide sharp detection thresholds for finite-rank perturbations, such as the known Baik-Ben Arous-P\'ech\'e (BBP) transition, they are often insufficient for realistic data exhibiting nearly continuous (extensive-rank) signal distributions that merge with the noise bulk. In this regime, typically associated with real-world scenarios such as images for computer vision tasks, the signal does not manifest as a clear outlier but as a deformation of the spectral density's geometry. We use the functional renormalisation group (FRG) framework to probe these subtle spectral deformations. Treating the empirical spectrum as an effective field theory, we define a scale-dependent "canonical dimension" that acts as a sensitive order parameter for the spectral geometry. We show that this dimension undergoes a sharp crossover, interpreted as a "dimensional phase transition", at signal-to-noise ratios significantly lower than the standard BBP threshold. This dimensional instability is shown to correlate with a spontaneous symmetry breaking in the effective potential and a deviation of eigenvector statistics from the universal Porter-Thomas distribution, confirming the consistency of the method. Such behaviour aligns with recent theoretical results on the "extensive spike model", where signal information persists inside the noise bulk before any spectral gap opens. We validate our approach on realistic datasets, demonstrating that the FRG flow consistently detects the onset of this bulk deformation. Finally, we explore a formalisation of this methodology for analysing nearly continuous spectra, proposing a heuristic criterion for signal detection and a method to estimate the number of independent noise components based on the stability of these canonical dimensions. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2506.02888 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2506.02888v2 Announce Type: replace-cross Abstract: We present a universal thermodynamic framework for quantum systems that may be strongly coupled to thermal environments. Unlike previous approaches, our method enables a clear definition of thermostatic properties while preserving the same gauge freedoms as in the standard weak-coupling regime and retaining the von Neumann expression for thermodynamic entropy. Furthermore, it provides a formulation of general first and second laws using only variables accessible through microscopic control of the system, thereby enhancing experimental feasibility. We validate the framework by applying it to a paradigmatic model of strong coupling with a structured bosonic reservoir. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2503.14645 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2503.14645v2 Announce Type: replace-cross Abstract: We introduce parallel-sequential (PS) circuits, a family of quantum circuit layouts that interpolate between brickwall and sequential circuits, which introduces control parameters governing a trade-off between the amount of entanglement and the maximum correlation range they can express. We provide numerical evidence that PS circuits can efficiently prepare many-body ground states in one dimension. On noisy devices, characterized through both idling errors and two-qubit gate errors, we show that in a wide parameter regime, PS circuits outperform brickwall, sequential, and the log-depth circuits from [Malz, Styliaris, Wei, Cirac, PRL 132, 040404 (2024)]. Additionally, we demonstrate that properly chosen noisy random PS circuits suppress error proliferation and, when employed as a variational ansatz, exhibit superior trainability. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2503.07720 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2503.07720v2 Announce Type: replace-cross Abstract: We introduce a variational algorithm based on the quantum alternating operator ansatz (QAOA) for the approximate solution of computationally hard counting problems. Our algorithm, dubbed VQCount, is based on the equivalence between random sampling and approximate counting and employs QAOA as a solution sampler. We first prove that VQCount improves upon previous work by reducing exponentially the number of samples needed to obtain an approximation within an arbitrary small multiplicative factor of the exact count. Using tensor network simulations, we then study the typical performance of VQCount with shallow circuits on synthetic instances of two #P-hard problems, positive #NAE3SAT and positive #1-in-3SAT. We employ the original quantum approximate optimization algorithm version of QAOA, as well as the Grover-mixer variant which guarantees a uniform solution probability distribution. We observe a tradeoff between QAOA success probability and sampling uniformity, which we exploit to achieve an empirical efficiency gain over both naive rejection sampling and Grover-based quantum counting. Our results highlight the potential and limitations of variational algorithms for approximate counting. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2108.10000 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2108.10000v2 Announce Type: replace-cross Abstract: Cancer cell populations often exhibit remarkably similar growth laws despite their heterogeneity. Explanations of universal cell population growth remain partly unresolved to this day. Here, we present a growth-law unification by investigating the connection between microscopic assumptions and the expected contact inhibition, which leads to five classical tumor growth laws: exponential, radial growth, fractal growth, generalized logistic, and Gompertzian growth. All five can be seen as manifestations of a single microscopic model. Agent-based simulations substantiate our theory, and we can explain differences in growth curves in experimental data from em in vitro cancer cell population growth. Thus, our framework offers a possible explanation for many mean-field laws used to empirically capture seemingly unrelated cancer or microbial growth dynamics. Our results highlight that the interplay between contact inhibition and other assumptions (e.g., well-mixed) can influence our quantitative understanding of how cancer cells grow and, in turn, how they may interact. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.10536 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.10536v2 Announce Type: replace Abstract: Using nonequilibrium and equilibrium molecular dynamics simulations, we investigate heat conduction in a momentum-conserving mesoscopic fluid modeled by multiparticle collision dynamics. Across quasi-two-dimensional (q-2D) to three-dimensional (3D) systems, we identify three distinct transport regimes: (i) a \emph{ballistic regime}, where thermal conductivity scales linearly with system size ($\kappa \sim L$) and the total heat current autocorrelation function $C(t)$ remains constant; (ii)~a \emph{kinetic regime}, characterized by size-independent $\kappa$ and exponentially decaying $C(t)$, demonstrating that normal heat conduction dominated by kinetic effects is far more ubiquitous than previously observed in 1D systems; and (iii)~a \emph{hydrodynamic regime}, where the q-2D system exhibits logarithmically divergent conductivity ($ \kappa \sim \ln L $ ) with $ C(t) \sim t^{-1} $ , while the 3D system displays finite $ \kappa $ and $ C(t) \sim t^{-3/2} $. Our results, observed in the hydrodynamic regime, quantitatively validate the scaling predictions for heat transport and reveal a clear dimensional crossover -- from 2D-like anomalous transport to 3D Fourier behavior. These results lay a foundation for understanding thermal transport in q-2D to 3D systems and have practical implications for the design of micro- and nanoscale thermal devices. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2602.16060 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2602.16060v2 Announce Type: replace Abstract: In this study, a recently introduced order parameter called the weighted coordination number (WCN) was used to investigate the liquid-liquid (LL) phase separation, indicating temperature-dependent coarsening of the LL interface as a possible mechanism for the glass transition. A well-established glass-forming Kob-Andersen binary Lennard-Jones system was used in this study. The gas-liquid binodal line was reconstructed using WCNs, and the same approach was extended to study the liquid-liquid binodal line. Systems of various densities are instantaneously quenched from high to low temperatures where liquid-liquid separation is observed. The densities and composition of each liquid state were used to verify the level rule, along with the density and pressure profiles, demonstrating the local equilibrium of liquid-liquid phase separation. The transition from the liquid-liquid phase separation in the supercooled region to the glass transition region was modeled by adopting a Markov Network Model to estimate the temperature-dependent viscosity using liquid-liquid interfacial information from the classification. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2601.14387 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2601.14387v2 Announce Type: replace Abstract: Energy costs of information processing are growing exponentially. Bit erasure is a key problem in this energy-information nexus, and a number of seminal relationships have been deduced regarding the relationship between thermodynamic costs and memory storage. To continue making progress in the modern era, however, requires confronting thermodynamic costs in realistic physical systems which operate away from equilibrium. Here, we explore the thermodynamic costs of bit erasure in a complementary metal oxide semiconductor model of two types of random access memory. We find dynamic random access memory dissipates the least amount of energy when operated in the quasistatic limit, where errors are also minimized. By contrast, static random access memory is most efficiently operated in finite time due to the energy required to maintain the state of the bit. We demonstrate a numerically robust optimization scheme using mean field theory and automatic differentiation, finding optimal protocols compatible with electrical engineering insights. These results provide a framework for operating realistic circuits in thermodynamically advantageous ways. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2510.25454 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2510.25454v3 Announce Type: replace Abstract: We study the role of fluctuations in particle systems modeled by Dean-Kawasaki-type equations, which describe the evolution of particle densities in systems with Brownian motion. By comparing microscopic simulations, stochastic partial differential equations, and their deterministic counterparts, we analyze four models of increasing complexity. Our results identify macroscopic quantities that can be altered by the conserved multiplicative noise that typically appears in the Dean-Kawasaki-type description. We find that this noise enhances front propagation speed in systems with density-dependent diffusivity, accelerates the onset of pattern formation in particle systems with nonlocal interactions, and reduces hysteresis in systems interacting via repulsive forces. In some cases, it accelerates transitions or induces structures absent in deterministic models. These findings illustrate that (conservative) fluctuations can have constructive and nontrivial effects, emphasizing the importance of stochastic modeling in understanding collective particle dynamics. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2509.24985 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.24985v2 Announce Type: replace Abstract: In complex ecological communities, species may self-organize into clusters or clumps where highly similar species can coexist. The emergence of such species clusters can be captured by the interplay between neutral and niche theories. Based on the generalized Lotka-Volterra model of competition, we propose a minimal model for ecological communities in which the steady states contain self-organized clusters. In this model, species compete only with their neighbors in niche space through a common interaction strength. Unlike many previous theories, this model does not rely on random heterogeneity in interactions. Even in this minimal model where only the common interaction strength is varied, we find an exponentially large set of states that exhibit a rich variety of cluster patterns with different sizes and combinations. There are sharp phase transitions into the formation of clusters. There are also multiple phase transitions between different sets of possible cluster patterns, many of which accumulate near a small number of critical points. We analyze this phase structure using both numerical and analytical methods. In addition, the special case with only nearest neighbor interactions is exactly solvable using the method of transfer matrices from statistical mechanics. We analyze the critical behavior of these systems. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.14110 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14110v1 Announce Type: cross Abstract: We derive deterministic equations for the evolution of non-Gaussian fluctuations in relativistic stochastic hydrodynamics. This is achieved by defining the average local Landau frame and corresponding fluctuating hydrodynamic variables. Fully nonlinear stochastic hydrodynamics is expressed in a unified multi-component matrix form. A novel relativistic formalism, also manifestly covariant under SO(3) rotations of the local spatial basis in the average local Landau frame, is introduced. The equations describe correlators of all hydrodynamic variables, including fluctuating velocity (or momentum density) -- a nontrivial problem in relativistic hydrodynamics. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13923 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13923v1 Announce Type: cross Abstract: We present a Krylov space based theoretical framework for modeling inhomogeneous spin ensembles with arbitrary distributions of spin frequencies and couplings. The framework is then used to asymptotically large spin ensemble. In the single-excitation subspace, the Krylov construction allows for to derive exact expressions for the Lieb-Robinson velocity and quantum speed limit, and figure of merit such as Krylov complexity. Our work reveals a strong dependence of the speed of information flow on the statistical distribution of resonance frequencies in the spin ensemble with immediate implications for the design of components for quantum technologies, realized for example with nitrogen vacancy centers, nuclear spins or ultracold atoms. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13615 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13615v1 Announce Type: cross Abstract: In nonlinear systems, small perturbations are conventionally attributed to negligible nonlinearity, justifying linear approximations. Here, we uncover a notable exception to this paradigm in an electrokinetic (EK) flow. Using a novel dual frequency excitation scheme with two high frequency AC electric fields ($> 10^{5}$ Hz), we efficiently excite flow perturbations at a difference frequency ($\Delta f$) four orders of magnitude lower. This approach reveals a strong nonlocal energy transfer mechanism mediated purely by the nonlinearity of the electric body force, enabling precise, clean flow control free from electrode polarization artifacts. Unexpectedly, these small, nominally linear velocity and electric conductivity fluctuations exhibit power law spectra. With increasing electric Rayleigh number, the scaling exponents agree quantitatively with predictions for fully developed EK turbulence by the Quad cascade process theory. This observation not only implies multiple flow state transitions even at low excitations, but also indicates that intrinsic nonlinearity regulates perturbations even in the linear regime, necessitating a fundamental re examination of linear approximations in electrohydrodynamics and other nonlinear systems. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13249 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13249v1 Announce Type: cross Abstract: We introduce a simulation technique to compute the free energy difference between two hydrate structures of different stoichiometry connected to a reservoir of gas molecules at a prescribed pressure. The method permits the determination of coexistence parameters for the system when the two hydrate structures have the same number of water molecules $N_w$. The approach is based on performing isobaric Lattice Switch Monte Carlo simulations to measure free energy differences between the hydrate structures when they are either fully occupied by gas molecules, or fully empty. This measurement is combined with thermodynamic integration within an ensemble in which the number of guest molecules $N_g$ can fluctuate under the control of a chemical potential $\mu_g$. We analyze the properties of the resulting constant-$N_w,\mu_g,P,T$ ensemble and show how it can be used to calculate coexistence points via a thermodynamic cycle. Applying the method to argon and methane structures, we find coexistence pressures that are in good agreement overall with the available experimental data. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13172 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13172v1 Announce Type: cross Abstract: We establish a rigorous relation between the thermalization of typical initial states and the dynamics of local operators. We introduce a concept of simple slow operators (SSOs), defined as operators that have a small commutator with the Hamiltonian and have significant small-sized components. We show that if typical initial states (drawn from a low-complexity state ensemble) do not thermalize on timescale $t$, then SSOs must exist that are approximately conserved up to timescale $t$. Equivalently, the absence of SSOs implies that typical initial states thermalize. We establish these results by introducing the concept of an ensemble variance norm of an operator, defined as the typical magnitude of the expectation value of that operator with respect to states in the ensemble. For low-entanglement ensembles, the norm is related to operator sizes, allowing us to establish a direct link between operator growth and thermalization. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.14143 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14143v1 Announce Type: new Abstract: We construct upper bounds on entanglement entropies of many-body quantum states that have fixed energy expectation values with respect to geometrically local Hamiltonians. Our focus is on entanglement entropies of subsystems that make up approximately half of the full system. The upper bound on the von Neumann entanglement entropy is half the sum of the thermal entropies of two fictitious systems at the same temperature as one another, with an additional area-law contribution in some systems. The effective temperature is chosen such that the sum of the thermal energies of the two fictitious systems matches the constraint on the energy of the state in the original problem; at subextensive energies, this temperature decreases with increasing system size. Our upper bounds on R\'{e}nyi entanglement entropies take an analogous form. As a first application we show that ground-state Schmidt ranks in frustration-free (FF) systems are upper bounded by the ground-state degeneracies of Hamiltonians acting on subsystems. Ground-state von Neumann and R\'{e}nyi entanglement entropies therefore follow an area law when the zero-temperature thermal entropies of subsystems scale with surface areas, rather than with subsystem volumes. This result holds independently of the spectral gap. For physical models of quantum matter, which have well-defined specific heat capacities (and are not necessarily FF), our bounds provide a way to convert this thermodynamic data into constraints on pure-state entanglement at both subextensive and extensive energies. We also show that our upper bounds on half-system entanglement entropies are optimal, up to subleading corrections, in wide varieties of systems. Our results relate physical thermodynamic properties to the structure of many-body Hilbert space at low energies. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13885 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13885v1 Announce Type: new Abstract: We study the role of heterogeneous volatility in a networked wealth dynamics model and its impact on the wealth condensation transition. Extending the Bouchaud--M{\'e}zard framework, we introduce binary volatility in networks and investigate how its configuration affects the effective power-law tail exponent of the wealth distribution. Using a stochastic block model, we control the mixing between volatility groups and show that the effective exponent is governed not only by the global parameter $\Lambda=2J/\beta^2$ but also by the volatility configuration in the network. We find that local interactions between nodes with different volatility induce a neutralization of group-wise exponents, which lowers the aggregate tail exponent and can drive a condensation transition across $\gamma_{\rm c}=2$. Our results identify volatility mixing as another control mechanism for wealth condensation and highlight the importance of noise heterogeneity in nonequilibrium systems on networks. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13164 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13164v1 Announce Type: new Abstract: Unstable periodic orbits act as organizing structures for classical chaotic systems and underpin quantum scarring. Long known in single-particle systems, genuine quantum scars based on unstable periodic orbits have been recently extended to isolated many-body systems for time-independent Hamiltonians. Their fate under periodic driving, however, remains largely uncharted, challenged by the expectation that these systems should in general heat to infinite temperature. Here, we investigate how genuine scarring competes with the drive in a Floquet many-body system. Using chaotic spin chains, we demonstrate that Floquet states remain scarred in the high-frequency limit. Beyond this static correspondence, we uncover additional, driving-induced Floquet scars with no static analog. We construct a rich dynamical stability diagram with intermediate-frequency regimes of enhanced and quenched scarring, which we understand with a classical analysis of the Lyapunov exponent. Our results position Floquet systems as a natural platform for tuning the scarring behavior of quantum many-body systems. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2603.22849 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.22849v3 Announce Type: replace-cross Abstract: Platinum oxides are vital catalysts, but their limited thermal stability hinders applications. Recent studies have uncovered a structural transition in two-dimensional platinum oxides that significantly enhances their thermal resilience by several hundred Kelvin. Herein, we demonstrate that this enhanced stability stems from the mechanical robustness of the elastic network at the atomic scale. Prior to the transition, an over-constrained lattice generates localized states of self-stress through an incommensurate Moir\'{e} pattern with the platinum substrate, reducing thermal endurance. After the transition, the oxide shifts to a mechanically flexible structure with balanced degrees of freedom and constraints. The isostatic network, together with the platinum substrate, forms a commensurate Moir\'{e} superlattice that relaxes elastic energy and enhances stability. These findings highlight the fundamental role of network connectivity in governing thermal stability, and provide a design principle for catalysts in extreme environments. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2506.18127 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2506.18127v2 Announce Type: replace-cross Abstract: We propose a non-integer-dimensional spatial model for anisotropic solids by incorporating a q-deformed derivative operator, inspired by the Tsallis nonadditive entropy framework. This generalization provides an analytical framework to explore anisotropic thermal properties, within a unified and flexible mathematical formalism. We derive explicit expressions for the phonon density of states and specific heat capacity, highlighting the impact of the deformation parameter q on the thermodynamic behavior. We apply the model to various solid-state materials, achieving excellent agreement with experimental data across a wide temperature range, and demonstrating its effectiveness in capturing anisotropic and subextensive effects in real systems. Beyond providing accurate fits, we anchor the q-deformation in a microscopic disorder/kinetics exponent \mu emerging from conformable dynamics, thereby linking nonextensive statistics to measurable heterogeneity and memory effects. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.09506 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.09506v2 Announce Type: replace Abstract: Active matter systems typically exhibit a trade-off between structural robustness and dynamical freedom, limiting independent control over structure and motion. Here, we show that encoding interactions in a shared field overcomes this constraint, enabling continuous tuning between stable architectures and dynamically active states. Using droplets on a vibrated fluid bath as a minimal realization, we demonstrate that individually unstable units can collectively self-stabilize through field-mediated dynamical bonds. Arising from wavefield interference, these bonds form persistent, self-healing connections that preserve architecture while sustaining motion. Droplet size sets the symmetry of the interactions, with identical droplets forming rigid $\sigma$-like frameworks that enforce triangular packing, while smaller droplets enable $\pi$-like coordination that supports higher-order symmetries. The resulting assemblies exhibit both stability and sustained collective dynamics, including spontaneous rotation and controlled migration. This work establishes a general route to programmable active matter in which shared fields reconcile structural robustness with dynamical freedom. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.03516 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.03516v2 Announce Type: replace Abstract: Deep-subwavelength acoustic resonators are key building blocks of acoustic metamaterials, yet achieving bubble-like resonances in air remains challenging because the Minnaert mechanism relies on the inertia of a surrounding liquid. Here we demonstrate that air-filled soft elastomer shells, termed elasto-bubbles, realize an airborne analogue of the Minnaert resonator. Using impedance-tube measurements together with the theory of layered-bubble scattering, we show that these soft hollow capsules sustain strong monopolar resonances despite being deeply subwavelength. Their resonance frequency, transmission dip, and absorption are quantitatively captured, without adjustable parameters, by a model accounting for shell elasticity and viscoelasticity. Because shell radius and thickness can be tuned independently during fabrication, elasto-bubbles provide a simple and versatile platform for airborne acoustic metamaterials, resonant absorbers, and acoustic filters. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.14056 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14056v1 Announce Type: cross Abstract: We investigate the thermal responses of a harmonic oscillator chain coupled at its boundaries to heat baths held at different temperatures. This setup sustains a steady energy flux, continuously dissipating heat into both reservoirs. By introducing slow variations in the bath temperatures, we quantify the resulting excess heat currents and thereby obtain the nonequilibrium heat capacity matrix at fixed but arbitrary temperature differences. We demonstrate the existence of a well-defined thermodynamic limit for long chains. The specific heat associated with energy exchanges with a single bath depends on the difference in friction coefficients governing the system-bath couplings. That thermokinetic effect is typical for nonequilibrium response. When the couplings with the thermal baths acquire temperature dependence, the specific heat correspondingly inherits a nontrivial temperature dependence, in sharp contrast with equilibrium. Our results provide the first explicit determination of specific heat(s) in a locally interacting, spatially extended driven system. Beyond its exact solvability, the model may offer a natural nonequilibrium extension of the Dulong-Petit law, capturing the high-temperature behavior of driven molecules. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13929 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13929v1 Announce Type: cross Abstract: Porous monolithic photocatalysts based on anatase TiO2 in silica aerogels are promising for air purification. Their bicontinuous spinodal architecture offers high surface area and strong light scattering. However, extracting intrinsic kinetic rates requires accurate optical models. Current methods replace the complex 3D pore network with a homogeneous 1D slab, an approximation whose error is unknown for spinodal geometries. We combine 3D spinodal masks from Cahn-Hilliard simulations with GPU Monte Carlo photon transport to quantify this. We introduce a solid-phase fluence estimator that accounts for catalytic site distribution, comparing it to volume averages and diffusion approximations. The solid phase receives 50% more photons than volume averages at porosity 0.70, rising to 70% at 0.90. This preferential illumination stems from quasi-ballistic paths through pore channels, termed photon channelling. The extracted kinetic descriptor differs by 34% between 3D Monte Carlo and diffusion models. Homogeneous controls show that roughly 50% of the total 73% discrepancy is intrinsic to the bicontinuous structure and cannot be fixed by effective medium theories. These results provide the first quantitative correction for kinetic extraction in such photocatalysts and establish design rules linking synthesis coarsening, pore size, and light efficiency. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13659 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13659v1 Announce Type: cross Abstract: The dynamics of water in electrolyte solutions exhibits a striking, ion-specific anomaly: the diffusion coefficient of water is enhanced relative to the neat liquid in chaotropic CsI solutions, yet suppressed in kosmotropic NaCl solutions. This phenomenon, long challenging for classical force-field-based molecular dynamics, is studied here using classical molecular dynamics simulations with a many-body machine-learned force field (MLFF) trained within the MACE equivariant graph neural network framework. The force field is trained on energies, forces, and stresses computed at the density functional theory level with the revPBE-D3 exchange--correlation functional, which provides a reliable balance between accuracy and computational efficiency for aqueous systems. Simulations of NaCl and CsI aqueous solutions at ambient conditions over a concentration range of 0.89--3.56~mol/kg reproduce the experimentally observed anomalous diffusion and show a quantitative improvement over previous results obtained with the DeePMD framework, trained on the same theory, particularly for NaCl solutions. This improvement is traced to a stronger Na$^{+}$--water interaction in the first hydration shell and the non-negligible retarding contribution of the second hydration shell of Na$^{+}$. For CsI solutions, the water acceleration is shown to be primarily driven by the anion I$^{-}$, whose diffuse and weakly structured hydration shell facilitates rapid water exchange with the bulk. These results are rationalised through a shell-decomposition analysis of time-dependent water diffusivities and ion--oxygen potentials of mean force providing a coherent microscopic picture of the acceleration--retardation mechanism in the studied aqueous electrolytes. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.14109 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14109v1 Announce Type: new Abstract: Granular flows are ubiquitous in nature and industrial applications, yet a complete continuum theory remains a long-standing challenge. The leading empirical approach, {\mu}(I) rheology, lacks microscopic foundations and becomes multivalued in dense, slowly sheared flows where nonlocal corrections are required. Exploiting state-of-the-art high-speed X-ray tomography to investigate microscopic dynamics of dense granular flows in a Couette geometry, we establish a new, universal constitutive law spanning quasi-static to inertial regimes based on structural relaxation, resolving the fundamental difficulty in the original {\mu}(I) framework. By further establishing a non-equilibrium statistical framework for granular flows, we demonstrate an intrinsic analogy between driven granular matter and hard-sphere liquids owing to their identical Carnahan-Starling equation of state, naturally explaining our rheological approach and the emergence of glassy behaviors. Our framework unifies granular rheology with the broader physics of disordered systems and provides a complete, microscopically-based theoretical framework for dense granular flow. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13827 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13827v1 Announce Type: new Abstract: Quantitative modeling has become an essential tool in modern biophysics, driven by advances in both experimental techniques and theoretical frameworks. Powerful high-resolution techniques now provide detailed datasets spanning molecular to tissue scales, allowing to visualize cellular structures with unprecedented detail. In parallel, developments in soft and active matter physics have established a robust theoretical basis for describing biological systems. In this context, two main modeling paradigms have emerged: particle-based models, which explicitly represent discrete components and their interactions, and continuum models, which describe systems through spatially varying fields. We compare these approaches across biological scales, highlighting their respective strengths, limitations, and domains of applicability. To keep our discussion biologically relevant, we focus on five systems of fundamental importance: the cytoskeleton, membranes, chromatin, biomolecular condensates and tissues. With this Review, we thus aim to provide a framework for both theorists and experimentalists to select appropriate modeling strategies, and highlight future directions in biophysical modeling. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13653 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13653v1 Announce Type: new Abstract: A ternary liquid crystalline mixture was designed to obtain a tilted hexatic smectic phase in the glassy state. Structural, electro-optic, and dielectric properties of the mixture are investigated, and selected measurements are also performed for its pure components. In particular, the electron density profile perpendicular to smectic layers is determined from the X-ray diffraction data and compared to the results of density functional theory calculations both for the mixture and pure components. Comparison of the experimental smectic layer spacing and tilt angle in the mixture allows us to assess whether molecular dimerization is likely to occur. On the mesoscopic scale, the helical pitch is determined in the SmC$_A$* phase of the mixture, and selective reflection of light is observed under a polarizing microscope in the SmC*, SmC$_A$*, and SmX$_A$* phases. The glass transition in the smectic X$_A$* phase is observed in calorimetric results. At the same time, the dielectric spectra do not directly reveal the primary $\alpha$-process, although the secondary $\beta$- and $\gamma$-processes are detected. Overall, the results show that the ternary mixture stabilizes a broad SmC$_A$* phase and enables vitrification of the hexatic SmX$_A$* phase, while the structural data suggest a change in the molecular organization between the SmC* and SmC$_A$* phases. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13575 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13575v1 Announce Type: new Abstract: In this perspective article, we discuss bacterial populations as a model system of active matter. It allows for the exploration and characterization of various phases of active matter and brings rich implications for both physics and biology. Specifically, we focus on active gas, active liquid, active glass and active liquid crystal states observed in bacterial populations and describe how these differ from their thermal counterparts. A few future directions are also discussed that will deepen the physical interest in active matter as a new type of material, with its implications for several life phenomena observed in bacterial populations and other biological systems. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13499 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13499v1 Announce Type: new Abstract: The sodium dodecyl sulfate (SDS) surfactant is widely used in various applications, such as household products (e.g., shampoos, toothpaste, detergents, and cleaning products) and food manufacturing (e.g., emulsifiers). To investigate its properties via computer simulation, various models have been developed, including coarse-grained (CG) models that are suitable for capturing a surfactant's self-assembly and fundamental properties for aqueous systems with a surfactant, such as surface tension. Here, we present a CG model for SDS/water systems for many-body dissipative particle dynamics (MDPD), which is based on the MDPD--Martini force field (FF). In the model, charged groups, namely, the SDS sulfate headgroup and the sodium cation, are explicitly modeled following the standard mapping of the Martini force field for molecular dynamics (MD), while the remaining interactions have been obtained from previous MDPD--Martini models for lipid systems, thus demonstrating their transferability. Various relevant system properties, such as the coherent scattered intensity and surfactant distribution at the liquid--vapor surface, are investigated, and results are compared to those obtained by MD simulations and experiments at different surfactant concentrations. Our findings indicate that MDPD--Martini models can offer a credible alternative to MD--Martini models for systems with explicit charges as shown here for SDS. Moreover, MDPD--Martini models reproduce nicely the experimental surface tension isotherm, in contrast to MD simulations. In view of the transferability of the MDPD--Martini interactions, the model parameters of this study can be tested and used to simulate a wider range of soft-matter systems. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13420 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13420v1 Announce Type: new Abstract: Freezing of complex fluids is central to a wide range of natural and technological processes, where the interplay between heat transport, solute redistribution, and interfacial deformation gives rise to complex morphologies. Unlike simple liquids, polymer solutions exhibit strongly coupled transport and rheological properties that evolve dynamically during solidification, making their freezing behavior difficult to predict. Here, we examine the freezing of polymer solution droplets spanning dilute to entangled regimes. We find that droplet morphology and freezing dynamics in viscous solutions are governed by a single dimensionless parameter, the Capillary--Lewis number, which captures the competition between viscous stresses, capillarity, and solute transport. Circularity, radial deformation, and freezing time collapse onto a master curve spanning nine orders of magnitude, revealing a transition near unity corresponding to the point at which solute diffusion can no longer relax concentration gradients ahead of the freezing interface. This collapse holds across distinct polymer chemistries within the viscous fluid regime, while deviations emerge when the material exhibits elastic-dominated response ($G' > G''$), indicating the breakdown of purely transport--capillary control. These results establish a minimal transport--mechanics framework linking solute redistribution to interfacial deformation during freezing polymer solutions. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13391 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13391v1 Announce Type: new Abstract: We study synchronization of two cardiomyocytes mediated by elastic interactions through the substrate. Modeling each cell as an oscillating force dipole governed by a Rayleigh-type equation, we derive an effective mechanical coupling from the elastic response of the surrounding medium. Using phase reduction theory, supported by direct numerical simulations, we obtain a dynamical phase description for two cardiomyocytes that predicts geometry-dependent selection of synchronized states. Depending on the mutual orientation, the cells robustly converge to either in-phase or anti-phase beating, yielding an orientation-dependent state map with a nontrivial state boundary. The synchronization time also depends strongly on the distance and mutual orientation of the cells. These results bridge earlier energetic two-body theory and dynamical single-cell theory, and provide a dynamical framework for elastic synchronization of cardiomyocytes. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2603.28849 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.28849v2 Announce Type: replace-cross Abstract: In one dimension, strongly correlated gapless systems are highly constrained due to conformal invariance, leading to the decoupling of low energy degrees of freedom corresponding to different symmetry sectors. The most familiar example of this is spin-charge separation. Here, we extend this mechanism to the non-Hermitian realm by demonstrating that skin effects corresponding to different symmetry sectors exhibit an emergent decoupling. We establish this for $N$ flavor fermions and demonstrate it numerically for the special case of the Hubbard model, in which spin and charge skin effects separate at low energies. Finally, we construct an interaction-enabled $E_8$ skin effect with no free fermion counterpart. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2512.07473 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2512.07473v3 Announce Type: replace-cross Abstract: We investigate the critical temperature of a relativistic Bose-Einstein condensate of charged bosons driven by rotation in a parallel magnetic field [Y. Liu and I. Zahed, Phys. Rev. Lett. 120, 032001 (2018)]. For non-interacting bosons, the critical temperature can only be determined for a system with fixed angular momentum. We find that the critical temperature of the non-interacting system vanishes due to the fact that the system is quasi-one-dimensional, indicating that non-interacting bosons cannot undergo Bose-Einstein condensation. For interacting bosons, we investigate a system with quartic self-interaction. We show that the order parameter vanishes and the off-diagonal long-range order is absent at any nonzero temperature because of the quasi-one-dimensional feature, in accordance with the Coleman-Mermin-Wagner-Hohenberg theorem. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2603.25784 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.25784v2 Announce Type: replace Abstract: Continuous control over lattice geometry, when combined with long-range interactions, offers a powerful yet underexplored tool to generate highly frustrated quantum spin systems. By considering long-range dipolar antiferromagnetic interactions on a breathed Kagome lattice, we demonstrate how these tools can be leveraged to stabilize a chiral spin liquid. We support this prediction with large-scale density-matrix renormalization group calculations and explore the surrounding phase diagram, identifying a route to adiabatic preparation via a locally varying magnetic field. At the same time, we identify the relevant low-energy degrees of freedom in each unit cell, providing a complementary language to study the chiral spin liquid. Finally, we carefully analyze its stability and signatures in finite-sized clusters, proposing direct, experimentally viable measurements of the chiral edge mode in both Rydberg atom and ultracold polar molecule arrays. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2603.25045 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.25045v2 Announce Type: replace Abstract: We investigate the dynamics of two identical spinless fermions on a one-dimensional lattice with open boundary conditions (OBC), subject to quasiperiodic long-range interactions. Using numerical exact diagonalization (ED), we study this non-integrable system as a continuous-time quantum walk and uncover a robust correlated dynamical regime. This regime, characterized by an approximately constant inter-particle distance, emerges under sufficiently strong quasiperiodic modulation of the long-range interactions. Further, the study shows that the behavior is determined by the nature of the interaction and the choice of boundary condition. Notably, by tuning the phase of the quasiperiodic modulation, we observe three distinct manifestations of this phenomenon: localization, nearest-neighbor separation oscillations, and next-nearest-neighbor separation transitions -- each arising for specific initial separations. Furthermore, we identify the suppression of entanglement entropy in the system, including instances of oscillatory behavior. Our results highlight how quasiperiodic long-range interactions shape few-body quantum dynamics. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2511.01138 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2511.01138v3 Announce Type: replace Abstract: Advances in experimental control of interacting quantum many-body systems with multiple tunable parameters-such as ultracold atomic gases and trapped ions-are driving rapid progress in quantum thermodynamics and enabling the design of quantum thermal machines. In this work, we utilize a sudden quench approximation as a means to investigate the operation of a quantum thermodynamic Otto cycle in which multiple parameters are simultaneously controllable. The method applies universally to many-body systems where such control is available, and therefore provides general principles for investigating their operation as a working medium in quantum thermal machines. We investigate application of this multi-parameter quench protocol in an experimentally realistic one-dimensional Bose gas, as well as in the transverse-field Ising model. We find that such a multi-parameter Otto cycle, when operating as an engine, outperforms not only its constituent single-parameter Otto cycles in terms of the net work and efficiency, but also the combined net work of its constituent engine cycles when added together independently. We also find that a similar multi-parameter enhancement applies to the coefficient of performance when the Otto cycle operates as a refrigerator. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13160 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13160v1 Announce Type: cross Abstract: We introduce a framework for realizing universal fermionic quantum processing with globally controlled itinerant fermionic particles. Our approach is tailored to the example of neutral atoms in optical lattices, but transposes to other setups with similar capabilities. We give constructive protocols to realize arbitrary fermionic processes, with time-dependent control over global parameters of the experimental setup, such as tunneling and interaction in a Fermi-Hubbard type model. We first prove the universality of our framework and then discuss implementation variants, such as hybrid analog-digital simulation of extended Fermi-Hubbard models, e.g., with long-range couplings. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14039 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14039v1 Announce Type: new Abstract: The interplay between charge and spin dynamics is at the heart of strongly correlated materials. Inspired by recent quantum simulation experiments, we develop a conserving diagrammatic method to describe the Fermi-Hubbard model for strong repulsion and small hole doping away from the half-filled anti-ferromagnetic ground state. We show that doping leads to four hole pockets in the Brillouin zone formed by magnetic polarons, which become increasingly damped with hole concentration. Likewise, the magnon spectrum of the anti-ferromagnet softens and dampens with doping due to hole-induced magnetic frustration. This gives rise to a suppression of the anti-ferromagnetic correlations in agreement with recent experiments. We then calculate the response of the system to a lattice modulation and recover the qualitative difference between in-phase and out-of-phase modulations seen in experiments, which was interpreted as signs of pseudogap physics. Our results indicate that the complex competition between spin and charge degrees of freedom and the emergence of the pseudogap phase may be usefully analyzed for small dopings, where systematic theories can be developed. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13370 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13370v1 Announce Type: new Abstract: Experiments on attractive Bose-Einstein condensates (BECs) have unlocked many intriguing out-of-equilibrium dynamics through the interplay between matter-wave dispersion and nonlinear attractive interaction. Competition between these effects leads to fascinating phenomena such as wave collapse, modulational instability, and formation of multidimensional bright solitons. This chapter reviews experimental studies on attractive condensates, with a primary focus on alkali atoms featuring two-body contact interactions. We review recent experimental advances in optical trapping and interaction control techniques, which have enabled new studies on attractive condensates in three and also in lower dimensions. Specifically, we discuss pioneering and recent experimental observations on the dynamics and stability of attractive BECs, including the formation of bright solitons, their collisions, and excitations in quasi-one-dimensional traps. Recent observations of the elusive two-dimensional Townes solitons and vortex solitons are also discussed in this Chapter. We then highlight an experimental technique revealing the nonclassical signatures of modulational instability in an attractive condensate. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13257 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13257v1 Announce Type: new Abstract: Arrays of Rydberg atoms provide a powerful platform for exploring constrained quantum dynamics and nonergodic many-body phenomena. While most work has focused on single-species systems, multispecies architectures offer additional interaction channels and enable new forms of dynamical constraints. We study the nonequilibrium dynamics of one-dimensional dual-species Rydberg chains of Cs and Rb atoms with species-dependent van der Waals interactions. Using large-scale matrix product state simulations, we show that the competition between intra-species repulsion and inter-species attraction induces dynamical fragmentation, marked by the coexistence of extended frozen regions and localized oscillatory sectors. The frozen regions act as emergent barriers that isolate and protect coherent dynamics. In the purely repulsive regime, we find that species-selective quenches drive spontaneous fragmentation, leading to dynamically disconnected regions with irregular revivals. These phenomena are robust across interaction regimes, revealing a universal mechanism for fragmentation and establishing multispecies Rydberg arrays as a versatile platform for exploring nonequilibrium quantum dynamics beyond single-species systems. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13892 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13892v1 Announce Type: cross Abstract: Time-resolved scanning near-field optical microscopy (tr-SNOM) enables the measurement of the dynamic optical response of functional surfaces beyond the diffraction limit. Experimental challenges are imposed both by the use of a pulsed light source, and by the need for interferometric signal modulation to isolate the near-field contribution. We present a novel experimental approach to retrieve the tr-SNOM signal using a 200 kHz laser system and pseudo-heterodyne modulation. We circumvent the Nyquist limit for spectral demodulation by sampling modulation phases, pump intensity and SNOM signal for every laser shot. A general time-resolved SNOM signal is derived, independent of detection scheme or physical assumptions about the near-field enhancement, and is successfully measured and isolated on WS$_2$ monolayer and multilayer regions. We confirm localization by signal-distance curves, spatial confinement at material boundaries, and by identifying signal contributions at individual modulation harmonics. Disentangling the dynamic contributions enables us to extract the dynamic dielectric function of the sample. Showing the capability of phase-domain sampling paves the way to integration of more diverse and specialized light sources, growing the potential of optical ultrafast near-field measurements. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13382 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13382v1 Announce Type: cross Abstract: We investigate a many-body interacting system of quantum kicked rotors, where each rotor resides in its respective quantum resonance. Rich many-body dynamics are found to emerge from the interplay between the principal and secondary resonances. In particular, for both the wavepacket and bipartite entanglement entropy, we analytically demonstrate three distinct dynamical regimes -- quadratic spreading (growth), period-2 oscillation, and their hybrid -- governed by the respective symmetries of the relevant potentials. Based on these symmetries, the connection between the wavepacket and the entanglement dynamics is illustrated. Other related issues are also discussed, including higher-order resonance effects, the robustness of the predicted dynamical behaviors, extension to many-body kicked tops, and relevance to experimental studies. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13379 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13379v1 Announce Type: cross Abstract: Chern insulator systems are realizable in numerous physical systems and can support robust nonreciprocal transmission of energy. A routing functionality constructed from two counter-oriented Chern insulator regions, using coupled Haldane type systems is proposed. By adjusting the strength of a magnetic field and the frequency of an antenna source, it possible to steer the flow of energy: completely to the left, completely to the right, or split. Alternatively, two sources can be used to direct the flow of energy. This formulation has the potential to serve as a robust and reconfigurable component in optical transmission. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13110 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13110v1 Announce Type: cross Abstract: In a recent work, Somogyfoki et al. (J. Non-Equilib. Thermodyn. 50, 59-76, 2025) analysed the linear stability of homogeneous equilibrium in third-order non-Fourier heat conduction within the framework of non-equilibrium thermodynamics with internal variables. They identified a stability condition, their equation (49), which could not be derived from the standard thermodynamic inequalities for the 2X2 conductivity blocks, and concluded that the Second Law does not guarantee stability in the most general case. Here we show that this conclusion was due to an overly conservative proof strategy: the standard thermodynamic conditions (concave entropy and non-negative entropy production, as expressed by the $2\times2$ block positive-definiteness inequalities (19)-(20) of the original paper) do suffice for linear stability. The key observation is that all coefficients of the dispersion polynomial remain positive for all physical wave numbers because their structure prevents positive real roots. This result confirms that thermodynamics, understood as a stability theory, ensures fundamental dynamic stability in all thermodynamically consistent third-order extended heat conduction theories. A comparison with the rate-equation approach of Giorgi, Morro and Zullo (Meccanica 59, 1757-1776, 2024) is also presented. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13808 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13808v1 Announce Type: cross Abstract: When charged particles are subjected to strong magnetic fields, they form discrete energy levels known as Landau levels. The Landau levels consist of a series of degenerate states of Landau modes, making them a promising platform for large-capacity information processing. However, to date, exploiting the high-order Landau modes and control their spatial distributions has remained elusive. Here, we propose to construct magnetic fields, electric fields, and imaginary momentum simultaneously to reshape high-order Landau modes in non-Hermitian systems. By building a non-Hermitian electric circuit platform, we experimentally realize pseudomagnetic fields via inhomogeneous coupling and pseudoelectric fields via a gradient on-site potential, while simultaneously introducing an imaginary momentum via non-reciprocal coupling. We directly observe multi-frequency single-peak localization of high-order Landau modes. Our work provides a universal method for manipulating high-order Landau modes and exploring applications in nonHermitian systems, such as frequency multiplexing and wave packet reshaping. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13775 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13775v1 Announce Type: cross Abstract: Nanoplasmonic modification of scintillation has so far been explored mainly in the weak-coupling regime, where changes in the local density of optical states enhance radiative recombination via Purcell-type rate engineering. By contrast, strong light-matter coupling generates hybrid states that modify emission dynamics beyond simple decay-rate acceleration, but its implications for scintillator nanocrystals (NCs) under ionizing radiation remain poorly understood. All of these effects are beneficial for near-infrared scintillators, which are typically slow and have low brightness. Here, we present a quantum-optical framework to investigate how near-infrared scintillator NCs coupled to nanoplasmonic antennas evolve from weak coupling toward strong light-matter coupling. We compare broad- and narrow-antenna platforms with single and periodic Au nanorods and benchmark them against conductive plasmonic antennas based on indium tin oxide and graphene. As representative emitters, we consider wide-band PbS NCs and narrow-band cubic Lu2O3:Er3+ scintillators. The calculations show that the onset of strong-coupling signatures is jointly governed by emitter dephasing and the antenna linewidth, with narrow-band emitters coupled to spectrally narrow antennas providing the most favorable conditions. Among the platforms considered, graphene gives the lowest threshold (g = 4 meV) for observable coherent exchange owing to its ultranarrow antenna linewidth (\k{appa} = 3.5 meV). These results identify near-infrared conductive nanoantennas, particularly graphene-based ones, as promising platforms for accessing hybrid scintillation regimes relevant to radiation detection. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13744 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13744v1 Announce Type: cross Abstract: Multilayered thin-film structures are frequently encountered in industrial applications, where accurate thermal property characterization is essential for performance optimization. These films, typically ranging from nanometers to micrometers in thickness, often exhibit anisotropic thermal conductivity and non-bulk heat capacity, which are challenging to measure. In this study, we introduce a variable-spot-size and multi-frequency square-pulsed source (SPS) method for the simultaneous determination of anisotropic thermal conductivities, heat capacities, and interfacial thermal conductance in multilayered systems. By leveraging a broad modulation frequency range (1 Hz to 10 MHz) and tunable laser spot sizes, the SPS method enhances sensitivity to different thermal parameters across layers. We validate this approach on a silicon-on-insulator (SOI) sample comprising a 1.59 um Si layer, 1.03 um SiO2 layer, and a silicon substrate with a 122 nm aluminum (Al) transducer. The SPS method successfully extracts seven key thermal parameters, including the in-plane and cross-plane thermal conductivities and heat capacity of the Si film, the thermal conductivity and heat capacity of the SiO2 layer, the thermal conductivity of the substrate, and the interfacial thermal conductance between Al and Si. Temperature-dependent measurements from 80 to 500 K showed excellent agreement with literature values and first-principles predictions, confirming the method's accuracy and reliability. These results demonstrate the SPS method as a powerful tool for comprehensive thermal characterization of complex multilayered structures, with implications for both fundamental research and practical applications. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13741 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13741v1 Announce Type: cross Abstract: Solid-liquid interfacial thermal conductance (ITC) critically influences heat transport in microfluidic, electronic, and energy systems, yet most optical thermometry techniques are limited to specific metal-liquid interfaces. In this work, we introduce a universal broadband square-pulsed thermometry method that enables simultaneous quantification of ITC across a wide range of arbitrary solid-liquid interfaces, while also providing accurate measurements of nanoscale liquid-film thickness. To validate the method, we applied it to Al-water interfaces, yielding ITC values in the range of 50-55 MW m^(-2) K^(-1), consistent with prior studies. The technique also reveals markedly lower ITCs for glass-water (9.9 MW m^(-2) K^(-1)) and Si-water (5.7 MW m^(-2) K^(-1)), and further measurements on Al-silicone oil (~10 MW m^(-2) K^(-1)) and PMMA-silicone oil (~0.4 MW m^(-2) K^(-1)) extend the validation to highly viscous nonpolar liquids and polymer-liquid interfaces. These results highlight the capability of the method to capture thermal transport differences across diverse solid-liquid combinations. Further comparisons with acoustic/diffuse mismatch models and molecular dynamics simulations, together with theoretical analysis, highlight the influence of vibrational mismatch, wettability, and surface condition on interfacial thermal transport. This broadly applicable technique enables rapid, quantitative characterization of solid-liquid interfacial thermal transport, with broad implications for interfacial heat transfer science and technology. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13647 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13647v1 Announce Type: cross Abstract: To describe the interactions in magnetically soft particle systems either numerical full-field methods or dipole models are used. Whereas the former are computationally challenging, simple dipole interactions are largely underestimating the actual forces when particles get closer. Based on the full 2-body solution, an analytic approximation scheme for many-body full-field interactions is developed. The concept is formulated in terms of an improved operator that is equivalent to the classical dipole form. The full interaction operator allows to describe cluster formation and dispersion among particles in applied magnetic fields very compactly and highly efficient. In view of its simple 'dipole-like' form, the implementation is straightforward in many areas where magnetically soft objects are used. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13497 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13497v1 Announce Type: cross Abstract: Magnetic skyrmions and higher-order topological spin textures offer rich opportunities for multi-level information encoding, yet their deterministic stabilization and transformation under geometric confinement at room temperature remain poorly understood. Here, we demonstrate that geometric confinement acts as a robust and universal control parameter that governs a hierarchical transformation pathway of chiral spin textures in Pt/Co/W multilayer micro-tracks. As the confinement increases, extended labyrinth domains fragment into isolated skyrmions, followed by the systematic suppression of skyrmion pairs and the preferential stabilization of compact higher-order textures. We find that confinement strongly enhances the formation of skyrmioniums via recombination and promotes their subsequent evolution into uniform skyrmion bags by capturing additional skyrmions. Statistical analysis reveals a confinement-driven redistribution of topological populations, with skyrmion bags emerging as the dominant state in the narrowest tracks. Supported by micromagnetic simulations, our results establish geometric confinement as a deterministic selector of complex topological textures and reveal a previously unexplored route for engineering higher-order skyrmionic states at room temperature. These findings provide a scalable materials strategy for multistate skyrmion-based spintronic and memory architectures. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13429 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13429v1 Announce Type: cross Abstract: Coherent control of quantum materials has progressed along two major fronts: nonlinear phononics, which reshapes lattices to induce emergent states, and Floquet engineering, which tailors electronic band reconstruction via time-periodic driving. Both mechanisms face fundamental limitations at terahertz (THz) frequencies: phononic nonlinearities are intrinsically weak in standard lattices, while electronic Floquet states are often constrained by rapid decoherence upon light-off and by a scarcity of coherence-resolved, multi-correlation probes beyond (quasi-)stationary band structures. Here we report an extreme THz nonlinear-phononics mechanism in $\text{Ta}_\text{2}\text{NiSe}_\text{5}$, where a highly susceptible non-equilibrium electronic correlation bath dramatically amplifies lattice nonlinearities under coherent driving. Utilizing THz two-dimensional spectroscopy as a coherence-tomography tool, we resolve an exceptionally rich landscape of approximately 30 distinct multi-order quantum pathways, including high-harmonic phonon generation, multi-quantum coherences, and multi-wave anharmonic cross-mode mixing. The density and complexity of this extreme manifold establishes a new benchmark for THz nonlinear phononics, as the multi-order quantum pathways surpass the limits of conventional lattice responses. These high-order signals collapse above ~100~K, defining an electronic correlation scale of a coherence-imprinted hybrid electronic-phonon order that governs the sustainability of high-order quantum correlations and nonlinear pathways beyond linear and equilibrium responses. Our results establish a route for correlation-boosted, phonon-anchored periodic Hamiltonian engineering and for certifying such periodically-driven states via multi-correlation coherence tomography. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13222 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13222v1 Announce Type: cross Abstract: We propose a model that extends the standard depinning paradigm by incorporating an aging mechanism into the local pinning force. This favors oscillations between a stuck state of large pinning, and a slipping state of smaller pinning. We show that for mean field interactions between sites this mechanism can lead to the appearance of ``king avalanches" and global instabilities, producing a global oscillatory stick-slip stress regime. We construct the phase diagram for this mean field case and identify regions of smooth dynamics, pure stick-slip, and bistability. Crucially, when considering two-dimensional systems with short-range interactions we find that states of global stress oscillation persist, but in contrast to the mean field case, no system-size avalanches appear. Instead, we observe alternating temporal intervals of larger and lower avalanche activity that correlate with the stress oscillations. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13139 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13139v1 Announce Type: cross Abstract: Machine learning (ML) is transforming modern physics research, but practical, hands-on experience with ML techniques remains limited due to cost and complexity barriers. To address this gap, we introduce an affordable, autonomous, Internet-of-Things (IoT)-enabled experimental platform designed specifically for applied physics education. Utilizing an Arduino microcontroller, a customizable multi-wavelength light emitting diode (LED) array, and photosensors, our setup generates diverse, real-time optical datasets ideal for training and evaluating foundational ML algorithms, including traversal methods, Bayesian inference, and deep learning. The platform facilitates a closed-loop, self-driving experimental workflow, encompassing automated data collection, preprocessing, model training, and validation. Through systematic performance comparisons, we demonstrate the superior ability of deep learning to capture complex nonlinear relationships compared to traversal and Bayesian methods. At approximately $60, this open-source IoT platform provides an accessible, practical pathway for students to master advanced ML concepts, promoting deeper conceptual insights and essential technical skills required for the next generation of physicists and engineers. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14082 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14082v1 Announce Type: new Abstract: Materials discovery is fundamental to advance next-generation technologies as well as for sustainable and circular economy. Beyond computational screening, generative models are efficient at finding materials with desired properties, via multi-modal learning using multiscale data. This perspective examines the landscape of generative design for inorganic materials and discusses the integration of multi-modal learning with high-throughput experimental validation. We contextualize these challenges through the lens of a generative design framework as a unified approach to address the data-driven inverse design of functional materials. The central idea of the framework is constructed around a foundation AI model for inorganic materials interlinked deeply with various property databases and high-throughput experiments via a machine learning driven closed loop, which enables the framework to solve key challenges in functional materials. We argue that domain-specific implementations of such integrated workflows represent a promising pathway toward the unresolved challenge of data-driven inverse design for atom-engineered inorganic functional materials. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14078 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14078v1 Announce Type: new Abstract: Long-term chemical durability of glass, crucial for immobilizing nuclear waste, is governed by glass properties such as composition, surface geometry, as well as external factors like thermodynamic conditions and surrounding medium. Despite decades of research, there are no models that account for these intrinsic and extrinsic factors to predict the dissolution rates of glass compositions. To address this challenge, we evaluate the role of natural language embeddings capturing the synthesis and testing conditions in enhancing the predictability of glass dissolution. Evaluating the approach on hand-curated ~700 datapoints extracted from the literature, we reveal that the machine learning (ML) model including natural language embeddings (NLP-ML) outperforms classical ML model in predicting glass dissolution rate. Furthermore, we developed a generalizable ML model by transforming the compositional features to structural descriptors of glass alongside NLP-derived features, enabling extrapolation capability to glass compositions with completely new elements absent in the training data. Evaluating this model on a completely new dataset of glass compositions 34 chemical components in contrast to the training dataset that had only 28 components, we demonstrate that the model indeed exhibits generalizability to glass compositions that are out-of-distribution. Altogether, this integrated approach offers a pathway towards high-fidelity glass dissolution prediction and accelerate the discovery of novel glass compositions with tailored durability for sustainable nuclear waste management. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13960 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13960v1 Announce Type: new Abstract: Twist-engineering of topological phases in two-dimensional materials offers a powerful route to modulate electronic structure beyond conventional strain or chemical control. In particular, group 15 (pnictogens) monolayers such as bismuthene provide an ideal platform due to their strong intrinsic spin-orbit coupling (SOC) and robust topological character. Here, we investigate a previously unexplored heterostructure consisting of a $\beta$-bismuthene monolayer rotated by 30$^\circ$ on a planar bismuthene layer stabilized on a SiC(0001) substrate. Using first-principles calculations, we demonstrate that this specific rotational alignment induces a unique interlayer orbital hybridization which, combined with the strong SOC and the naturally broken inversion symmetry, gives rise to a pronounced Rashba spin-splitting, absent in the isolated monolayers. The topological nature of the system is confirmed through the calculation of the Z2 topological invariant and Spin Hall Conductivity (SHC), revealing a robust Quantum Spin Hall (QSH) phase with an enhanced topological response compared to the individual layers. Furthermore, we explore the chemical tunability of this system via Sb substitution, showing that the gradual reduction of SOC systematically narrows the band gap while preserving the non-trivial topology. Our results establish large-angle twisted group 15 heterostructures as a versatile platform for engineering spin-orbit-driven phenomena and advancing topological spintronics. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13948 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13948v1 Announce Type: new Abstract: The coexistence of topological states with different dimensionalities in a single crystalline system offers a unique platform to study the interplay of distinct fermionic excitations. Here, integrating first-principles calculations with symmetry analysis, we propose the three-dimensional boron allotrope $P6_3$-$\text{B}_{30}$ as an ideal, structurally stable candidate for exploring multidimensional topological physics. Benefiting from the practically negligible spin-orbit coupling of the light-element framework, $P6_3$-$\text{B}_{30}$ operates as a pristine spinless topological semimetal. We show that the combined time-reversal and twofold screw symmetry ($\mathcal{T}S_{2z}$) enforces a robust two-dimensional nodal surface on the $k_z = \pi$ plane via a Kramers-like degeneracy. Concurrently, the system hosts a diverse set of zero-dimensional Weyl fermions -- including an unconventional double-Weyl point ($\mathcal{C} = -2$), conventional Type-I WPs ($\mathcal{C} = -1$), and completely tilted Type-II WPs ($\mathcal{C} = +1$) -- emerging at the high-symmetry points $\Gamma$ and K, as well as along the H-K path, protected by $C_6$ and $C_3$ crystalline rotational symmetries. Crucially, the substantial momentum-space separation between the nodal surface and Weyl points allows for their unambiguous independent resolution. Calculations of the (100) surface states reveal distinct, nontrivial Fermi arcs connecting Weyl nodes of opposite chirality. This work establishes $P6_3$-$\text{B}_{30}$ as a compelling material platform for investigating the physics of multidimensional hybrid topological fermions and their interplay. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13931 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13931v1 Announce Type: new Abstract: Topologically nontrivial magnetic textures such as skyrmions offer promising opportunities for spintronic applications. In recent years, it has been shown that the magnetic properties of layered materials can be affected by depositing chiral molecules on the surface, while the influence of chiral overlayers on skyrmion properties such as their stability and interactions remains largely unexplored. To address this challenge, we employ wide-field nitrogen-vacancy (NV) magnetometry to directly image skyrmions in chiral-molecule-functionalized magnetic thin films, enabling quantitative mapping of magnetic stray fields over extended areas under ambient conditions. Using pixel-resolved optically detected magnetic resonance (ODMR) combined with controlled magnetic fields, we reproducibly nucleate and probe skyrmion states in CoFeB ferromagnetic samples, enabling quantitative investigation of their properties. We find evidence for enantioselective and magnetic-field-polarity-dependent modifications of skyrmion diameter, spacing, and shape, pointing to a possibility of molecular control of topological spin textures via magneto-chiral coupling. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13821 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13821v1 Announce Type: new Abstract: The coexistence of step bunching and step meandering remains contradictory in the understanding of the unstable step-flow growth. Considered separately, the two instabilities have generated rich but largely independent modeling traditions. Especially, the one-dimensional framework faces a fundamental difficulty once bunching and meandering occur simultaneously -- step bunching is usually associated with an inverted Ehrlich--Schwoebel effect, whereas step meandering is associated with a direct one. The key experiments also focus mainly on the two basic limiting cases. How, then, can both instabilities coexist within the same growth process once the simultaneous occurrence of bunching and meandering cannot be adequately captured as a simple superposition of the two? In this work, we confront results from two substantially different approaches: a (2+1)D Vicinal Cellular Automaton based model (VicCA) and a differential-difference PDE-based description combining a model of step bunching with a relaxation term in the perpendicular direction. The continuous framework enables to explore long-time scales evolution to find large variety of surface patterns. Introducing a proper shape of the potential energy landscape in the VicCA model produces similar patterns and links both models on the level of parameters. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13768 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13768v1 Announce Type: new Abstract: Chalcogenide perovskites have emerged as promising lead free materials for photovoltaic and thermoelectric applications. Among them, BaZrS3 has attracted particular attention due to its thermal and chemical stability, favorable optoelectronic properties, and low thermal conductivity. Here, we combine molecular dynamics and Monte Carlo simulations based on machine learned interatomic potentials with scanning transmission electron microscopy to investigate mixing thermodynamics and phase stability in the BaZr(S,Se)3 system. We identify an unusual ordered structure that persists at room temperature, most prominently at 33% S, where S and Se atoms form alternating layers within the crystal. Free energy calculations yield the temperature composition phase diagram, including a nonperovskite delta phase in the Se rich limit and a perovskite phase in the S rich limit, separated by a broad two phase region. Analysis of the dielectric function and the absorption coefficient demonstrates that composition, crystal structure, and anion ordering jointly control the optical band gap. Selenium alloying enables tuning between approximately 1.6 and 1.9eV, while anion ordering within a given composition reduces the gap by about 0.12eV. Lastly, variations between structural polymorphs give rise to band gap differences of up to 0.4eV. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13752 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13752v1 Announce Type: new Abstract: The physical properties of matter are typically described by coefficient matrices governed by crystal symmetry. Applying spatial operations, such as rotation, inversion, and mirror, to these matrices provides an effective approach for investigating material properties. However, the diversity of coefficient matrix types complicates their transformation via simple matrix multiplication, and existing methods suffer from cumbersome notation, high computational cost, and lack of intuitive interpretation. Moreover, as coefficient matrices grow in size, conventional approaches become increasingly inadequate. We present a generalized ``input-coefficient-output (ICO)" approach for constructing spatial operation matrices applicable to coefficient matrices across diverse physical systems, including but not limited to high-order nonlinear optics, elastic mechanics, electricity and magnetism. Our approach offers a concise formalism that enables intuitive reasoning about spatial transformations while delegating intensive computations to computational tools, which is analogous to the role of Feynman diagrams in facilitating understanding in physics. This method also offers valuable insights for future theoretical and experimental research. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13640 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13640v1 Announce Type: new Abstract: Van der Waals (vdW) heterostructures enable tailored electronic and magnetic phases by stacking atomically thin layers with pristine interfaces. Here, we investigate fully 2D Cr2Ge2Te6/WTe2 heterostructures and identify a strong enhancement of ferromagnetism in Cr2Ge2Te6 (CGT). Magnetotransport measurements across multiple devices with WTe2 thicknesses ranging from monolayer to bulk reveal a robust anomalous Hall effect together with a more than twofold increase of the Curie temperature and substantially enhanced coercive fields. Interface microscopy confirms chemically abrupt vdW interfaces with no detectable interdiffusion, while control experiments rule out processing- or stray-field-induced artifacts. Our experiments and theoretical calculations demonstrate that interfacial charge transfer renders CGT conductive and that proximity-induced lattice distortions in CGT enhance exchange and magnetocrystalline anisotropy. These results establish strain-mediated lattice reconstruction as a strategy for engineering high-temperature magnetic order in 2D heterostructures and clarify that modifications within the magnetic layer itself can govern proximity effects in vdW stacks. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13442 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13442v1 Announce Type: new Abstract: Lead-halide perovskites are a promising material platform as semiconductors in next-generation solar cells because of their solution processability, defect tolerance, and tunable optoelectronic properties. While iodide-bromide perovskite compositions have shown promise as wide bandgap absorbers, they also suffer from significant instabilities under operating conditions. Triple-halide perovskites, where chloride is additionally incorporated, have demonstrated improved stability and performance over their double-halide counterparts; however, relatively little is understood about halide miscibility and incorporation in these novel materials. While bulk metrics such as lattice spacing and optical bandgap can be consistent with incorporation of chloride into a single phase, these results are not sufficient to fully describe the material as having homogeneous mixing on the X site. This uncertainty motivates the use of a more local probe to study short-range halide coordination and illuminate the role of chloride in triple-halide perovskites. We use cryogenic X-ray absorption spectroscopy (XAS) to characterize lead-halide bonds in a range of single-, double-, and triple-halide perovskite compositions. We show formation of a single-phase triple-halide perovskite whose miscibility is mediated by bromide content. We identify signatures of halide mixing from the Pb L3-edge EXAFS of mixed double- and triple-halide perovskites using both quantitative fits and Cauchy wavelet transforms. Finally, using wavelet transforms of the Br K-edge EXAFS, we demonstrate via forward scattering amplified 3rd shell halide-halide interactions that all three halides coordinate at short range in a fully mixed perovskite phase. These results are a step forward in the understanding of local structure that is required to fully describe and optimize halide incorporation for novel perovskite compositions. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13354 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13354v1 Announce Type: new Abstract: The discovery of inorganic crystal structures with targeted properties is a significant challenge in materials science. Generative models, especially state-of-the-art diffusion models, offer the promise of modeling complex data distributions and proposing novel, realistic samples. However, current generative AI models still struggle to produce diverse, original, and reliable structures of experimentally achievable materials suitable for high-stakes applications. In this work, we propose a generative machine learning framework based on diffusion models with adaptive constraint guidance, which enables the incorporation of user-defined physical and chemical constraints during the generation process. This approach is designed to be practical and interpretable for human experts, allowing transparent decision-making and expert-driven exploration. To ensure the robustness and validity of the generated candidates, we introduce a multi-step validation pipeline that combines graph neural network estimators trained to achieve DFT-level accuracy and convex hull analysis for assessing thermodynamic stability. Our approach has been tested and validated on several classical examples of inorganic families of compounds, as case studies. As a consequence, these preliminary results demonstrate our framework's ability to generate thermodynamically plausible crystal structures that satisfy targeted geometric constraints across diverse inorganic chemical systems. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13657 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13657v1 Announce Type: cross Abstract: Ultrasound-guided drug and gene delivery (USDG) is a promising non-invasive approach for targeted therapeutic applications. Mechanical properties of encapsulated microbubbles (EMBs), which serve as contrast agents, strongly affect their specific interactions with ultrasound and are thus critical to the success and efficiency of USDG. Accurate calibration of high-fidelity particle-based models of EMB capsid mechanics is computationally challenging because direct Bayesian inference with dissipative particle dynamics (DPD) is prohibitively expensive. We employ a surrogate-accelerated Bayesian calibration workflow that combines deep neural network (DNN) surrogates, transitional Markov chain Monte Carlo sampling, and hierarchical regularization across EMB diameters. Using this framework, we develop two data-informed DPD models of commercial EMB agents, i.e., Definity and SonoVue, and perform inference of force field parameters based on published compression experiments for Definity and indentation experiments for SonoVue, each spanning three distinct diameters. The inferred posteriors show that key model parameters, such as the stretching stiffness and bending modulus, are consistently constrained by the available data. The presented methodology can be used to derive bespoke, data-informed models for a wide range of ultrasound contrast agents, including encapsulated gas vesicles, EMBs with diverse capsids consisting of lipids, proteins, or polymers, and functionalized with ligands. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13644 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13644v1 Announce Type: cross Abstract: Spin qubits have emerged as a leading platform for quantum information processing due to their long coherence times, small footprint, and compatibility with the existing semiconductor industry. We first provide an introduction to the different qubit implementations currently being investigated, including single electron-spin qubits, hole-spin qubits, donor qubits, and multispin encodings. We discuss how the confinement and strain present in semiconductor heterostructures produce addressable levels whose spin degree of freedom can be used to encode a qubit. A large emphasis is placed on reviewing the theoretical foundations and recent experimental demonstrations of proposed mechanisms for long-range coupling, including hybrid approaches based on circuit QED and Andreev qubits, as well as spin shuttling. Finally, we review a recent proposal for linking spin qubits using topological spin textures. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13358 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13358v1 Announce Type: cross Abstract: If an operator $H$ anticommutes with a chirality operator $\Gamma_*$ such that $\Gamma_*^2=1$, the null space of $H$ can be decomposed in a direct sum of two spaces having positive and negative chiralities, respectively. When both spaces are finite dimensional, one can define an index, $\mathrm{Ind}(\Gamma_*,H)$, as the difference of dimensions of these two spaces. The key issue is whether $\mathrm{Ind}(\Gamma_*,H)$ is topologically protected, i.e., whether it remains constant under smooth variations of the parameters and background fields entering $H$. For Hermitian Dirac operators, topological protection of the index is guaranteed by the Atiyah--Singer theorem. In this paper, by using the heat kernel methods, we show that $\mathrm{Ind}(\Gamma_*,H)$ is topologically protected also for non-hermitian operators $H$ as long as they are diagonalizable and satisfy some ellipticity conditions. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13339 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13339v1 Announce Type: cross Abstract: Hydroxyapatite (HAp) is the primary mineral component of various mineralized tissues in the human body, including bone and teeth, where it performs critical roles of structural support and load transmission. In the context of dental health, the two most crucial properties of HAp are mechanical stability, which ensures resistance to forces, and chemical stability, which preserves surface integrity in acidic environments. During early stages of human evolution, e.g. when teeth were used to crush uncooked food, mechanical stability was of paramount importance. However, with changes in diet and lifestyle, the principal origins of tooth damage and loss shifted towards bacterially mediated chemical attack, known as tooth decay, or caries. To enhance the chemical stability, ion doping has emerged as a particularly significant approach, and it lies at the focus of the present study. A Molecular Dynamics (MD) framework was developed to investigate the effects of ion doping on the chemical and mechanical stability of HAp and to identify optimal doping candidates. The framework combines conventional MD with Steered Molecular Dynamics (SMD), Thermodynamic Integration (TI) and uniaxial compression test simulations to provide comprehensive insights into the doping process. The findings revealed surface atoms as the most viable candidates for doping, as demonstrated by SMD and conventional MD simulations. Notably, TI calculations have identified magnesium ions as a better candidate among the ions considered here for enhancing the chemical stability of HAp. The results presented in this study offer valuable guidelines for synthesizing HAp-based substituent materials with properties tailored to meet the demands of modern dental applications such as implant coatings, enamel remineralization agents and restorative materials. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14150 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14150v1 Announce Type: new Abstract: Non-Hermitian band descriptions capture how loss, gain, and environmental coupling reshape quantum matter, yet most experimental tests rely on wave-based or dynamical probes. Here we establish a new equilibrium route to exceptional physics in Dirac materials: in the weakly non-Hermitian regime, the thermodynamic density of states and the quantum capacitance exhibit a universal equilibrium approach to the exceptional point. In our minimal non-reciprocal graphene model, the hopping imbalance reduces the Dirac velocity as $v_F=v\sqrt{1-\beta^2}$, implying that the low-energy density of states, the thermodynamic density of states, and the quantum capacitance all scale as $(1-\beta^2)^{-1}$ as $|\beta|\to 1^-$. Consequently, at charge neutrality the quantum capacitance remains linear in temperature but with a diverging prefactor, while the inverse response softens linearly on approaching the exceptional point. In a magnetic field, this manifests as a collapse of the Landau-level spacing and a corresponding crowding of thermally active levels. Complementarily, the biorthogonal Bloch states exhibit a Petermann factor $K=(1-\beta^2)^{-1}$, which isolates the irreducibly non-Hermitian effect of eigenvector non-orthogonality. These results identify quantum capacitance as an experimentally accessible bulk equilibrium probe of effective non-Hermiticity in Dirac materials. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13945 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13945v1 Announce Type: new Abstract: Kitaev chains realized in quantum dots coupled via superconducting segments provide a controllable platform for engineering Majorana zero modes (MZMs). In these systems, subgap states in the hybrid region mediate the effective coupling between quantum dots and determine the emergence of sweet-spots where MZMs are strongly localized. However, existing minimal treatments often oversimplify the mesoscopic hybrid region. We perform a full microscopic treatment of this hybrid segment, capturing the quasiparticle continuum and spin-split Andreev bound states (ABSs), and show that it fundamentally alters the minimal picture. We derive analytical expressions for the renormalized couplings and sweet-spot conditions, establishing a direct link between microscopic chain parameters and Majorana optimization and identifying experimentally relevant regimes for improved device performance. Critically, we find that parity-crossings of the ABS, marking the onset of an odd-parity spin-polarized regime in the segment, identify the optimal operating windows where MZMs are simultaneously well localized with a large gap to excited states. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13936 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13936v1 Announce Type: new Abstract: We study a Su-Schrieffer-Heeger chain coupled to a single mode photonic cavity. Considering an off-resonant regime we use the high-frequency expansion in order to obtain an effective fermionic Hamiltonian with cavity-mediated interactions. We characterize the effects of the cavity on topology in a finite size chain by studying three different markers adapted for interacting systems: correlation functions between edges in a chain with open boundary conditions, and a winding number based on the single-particle Green's function and bulk electric polarization via the many-body formula by Resta for a chain with periodic boundary conditions. There is excellent agreement between the winding number and polarization approaches to compute the phase diagram, with the presence of the edge states being confirmed through the calculations of the two-point correlation function. Our approach provides an alternative perspective on cavity-modified topological phases through a study of an effective interacting electronic Hamiltonian and complements methods that treat the full light-matter Hamiltonian directly. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13920 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13920v1 Announce Type: new Abstract: Nonlinear modal interactions in resonant systems govern a wide range of phenomena, with broad relevance across modern physics and engineering. Yet, experimentally determining the strength of nonlinear coupling in multimode resonators remains highly challenging. Here, we introduce a multi-tone spectroscopy method for identifying nonlinear coupling coefficients directly from experimental data. Our approach employs dual-tone excitation near selected resonances which, in combination with additional probing tones at higher-order modes, generates sideband responses associated with specific modal couplings. These spectral signatures are analyzed using an inverse reconstruction procedure to quantitatively determine the corresponding nonlinear coupling strengths in the frequency domain. Using this method, we determine ten pairwise nonlinear coupling parameters across five modes of highly tensioned nanostrings, enabling the reconstruction of fully experimental, device-specific nonlinear reduced-order models. Our experimentally derived models show excellent agreement with values obtained numerically using finite element based nonlinear reduced-order models. Our method is generic and can be used for the characterization of diverse modal and intermodal couplings in mechanical and hybrid resonant systems. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13893 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13893v1 Announce Type: new Abstract: Quantum geometry, a quantum mechanical quantity comprised of Berry curvature and quantum metric, describes the geometric structure of the electronic bands in solids. The correlation between nontrivial quantum geometry and quantum materials leads to new findings in condensed matter systems. Here we demonstrate that altermagnets, with spontaneously broken time-reversal (T)- half-lattice-translation and parity-time symmetry, host both T-odd and T-even quantum geometric quantities that simultaneously manifest themselves despite the vanishing net magnetization. Consequently, giant room-temperature third-order electrical transport responses with sizable quantum geometric contributions are observed in (101)-oriented RuO2 thin films, an altermagnetic candidate; in particular, the third-order Hall effect is intimately correlated with altermagnetic order and can serve as a promising tool for detecting the Neel vector. Our work not only supports the existence of altermagnetism in 8-nm-thick RuO2 thin films, but also shows altermagnets as a versatile platform for exploring quantum geometry and constructing quantum electronic and spintronic devices. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13760 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13760v1 Announce Type: new Abstract: Spin shuttling has crystalized as a powerful and promising tool for establishing intermediate-range connectivity in semiconductor spin-qubit devices. Although experimental demonstrations have performed exceptionally well on different materials platforms, the question of how to handle areas of low valley splitting in silicon during shuttling remains unresolved. In this work, we explore the possibility of utilizing the valley degree of freedom, particularly in regions of low valley splitting, to allow mobile spin qubits to be shuttled through an occupied stationary quantum dot, thereby leapfrogging over the stationary electron. This not only grants a more enriched mobility for shuttled electrons, as it opens new possible routing paths, but also enables the implementation of an entangling SWAP$^\gamma$ two-qubit gate operation in the process. Simulating this process for different sets of parameters, we demonstrate the feasibility of such an operation and offer a unique use case for otherwise precarious regions of a quantum processor chip and propose a possible extension to the set of possible operations for silicon spin qubit devices. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13729 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13729v1 Announce Type: new Abstract: Light-matter interactions are governed by conservation laws of energy and momentum. For harmonic generation in crystalline solids, energy conservation imposes that $m$ incoming photons with energy $\hbar \omega_0$ are combined to form one photon at energy $m\hbar \omega_0$. Linear momentum conservation governs phase matching, whereas angular momentum conservation connects the angular momentum carried by photons to the discrete rotational symmetry of the crystal lattice. As a consequence, circular harmonic generation exerts a torque on the lattice and, conversely, a macroscopic rotation of the crystal induces a nonlinear rotational Doppler shift. These cornerstone laws of nonlinear optics rely on macroscopic symmetry arguments, and therefore provide little insight into the microscopic origin of angular momentum transfer. Here we uncover a direct connection between angular momentum conservation in nonlinear optics and the electronic quantum geometry, by proving that the transferred angular momentum from light to the crystal is proportional to the local Berry curvature at one optical resonance. This relation is encoded in the nonlinear harmonic circular dichroism, which we measure experimentally in an atomically thin semiconductor. With this, we extend our understanding of nonlinear optics, and we establish a method for the all-optical control and read-out of the local Berry curvature. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13682 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13682v1 Announce Type: new Abstract: We investigate the emergence of charge waves and their temporal dynamics in one-dimensional Su-Schrieffer-Heeger (SSH) topological chains. Contrary to the conventional view that charge oscillations are suppressed in gapped topological systems with preserved chiral symmetry, we show that such oscillations can indeed occur. The general condition for an arbitrary oscillation period is analysed, and we find that the charge waves propagating along the chain do not depend on its topology, except at the edges, where both topological phases exhibit essential differences. In chains with inequivalent atoms within the SSH unit cell, we observe regular long-period sublattice oscillations that appear simultaneously with even-odd charge oscillations. Furthermore, we study the nonequilibrium dynamics in SSH chains. After a quench, the time evolution of the local density of states and charge occupancies exhibits clear dynamical fingerprints that distinguish topologically trivial and nontrivial phases. Our results establish that transient charge dynamics can distinguish topologically trivial and nontrivial phases in real time by detecting the presence of topologically-protected edge states. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13662 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13662v1 Announce Type: new Abstract: Tuning of gate-defined semiconductor quantum dots (QDs) is a major bottleneck for scaling spin qubit technologies. We present a deep learning (DL) driven, semantic-segmentation pipeline that performs charge auto-tuning by locating transition lines in full charge stability diagrams (CSDs) and returns gate voltage targets for the single charge regime. We assemble and manually annotate a large, heterogeneous dataset of 1015 experimental CSDs measured from silicon QD devices, spanning nine design geometries, multiple wafers, and fabrication runs. A U-Net style convolutional neural network (CNN) with a MobileNetV2 encoder is trained and validated through five-fold group cross validation. Our model achieves an overall offline tuning success of 80.0% in locating the single-charge regime, with peak performance exceeding 88% for some designs. We analyze dominant failure modes and propose targeted mitigations. Finally, wide-range diagram segmentation also naturally enables scalable physic-based feature extraction that can feed back to fabrication and design workflows and outline a roadmap for real-time integration in a cryogenic wafer prober. Overall, our results show that neural network (NN) based wide-diagram segmentation is a practical step toward automated, high-throughput charge tuning for silicon QD qubits. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13661 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13661v1 Announce Type: new Abstract: Photoabsorption in the low-energy region for C$_{60}$ and PTCDA molecular complexes is studied within linear response TDDFT. For the PBE, B3LYP and HSE exchange-correlation (xc) functionals the dependence of the accuracy of the exciton energy on the electron-hole separation is analyzed. Particular attention is paid to the charge-transfer (CT) excitons. The inclusion of non-local exchange using hybrid functionals increases the accuracy of calculations for short-range excitons, however, the accuracy of hybrid functionals decreases significantly for long-range excitons. Moreover, as the exciton radius approaches the "screening length"\ , the simpler PBE functional gives more accurate excitonic energies than the mentioned hybrid functionals. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13532 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13532v1 Announce Type: new Abstract: Symmetry-protected topological phases of matter, characterized by non-trivial band topology, are spectrally gapped and show non-trivial boundary phenomena. Here, we show that scattering states when interjected by an array of periodically modulated defects can result in emergent topological phases whose properties can be tuned by modulating the defect strengths. We dub this the Su-Schrieffer-Heeger network. We show that a scattering-matrix network model can capture the emergent symmetries and nontrivial winding of the quasienergy bands, which lead to distinct transport signatures and can be further periodically driven to realize a robust Thouless charge pump. We show that a microscopic lattice model embedded with a defect superlattice yields Bloch minibands that directly map to the network problem. We further verify that the physics we report is stable to disorder and point out concrete experimental solid-state platforms where it is readily realizable. Our work, in contrast to engineering atomic Hamiltonians, shows that defect engineering on metallic platforms can lead to emergent topological phases of quantum matter. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13527 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13527v1 Announce Type: new Abstract: Two-dimensional phononic crystals (PnCs) formed by a periodic array of holes in a suspended membrane have previously been used to coherently control thermal conductance at low temperatures by modifying the phonon dispersion, thereby altering the phonon group velocities and the density of states. Here, in contrast, we demonstrate that PnCs formed by a periodic array of Al pillars on an uncut \SiN membrane can also be used to achieve similar coherent control. We have measured and simulated the thermal conductance of four pillar-based PnCs with different lattice constants ranging from 0.3 to 5 $\mu$m at sub-Kelvin temperatures, showing a strong up to an order of magnitude reduction in thermal conductance compared to an unaltered membrane. For the larger lattice constants $> 1 $ $\mu$m, however, the experiments do not agree with the coherent theory simulations, which we interpret as a breakdown of coherence induced by increasingly effective diffusive scattering due to the roughness of the Al pillar surfaces. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13451 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13451v1 Announce Type: new Abstract: We predict the emergence of nontrivial topological magnon states in the skyrmionium lattice with zero topological charge. We propose the concept of weighted magnetic flux, which provides a clear physical picture for this anomalous phenomenon. We also map the skyrmionium lattice onto the Haldane model, offering an alternative framework for interpreting this. Our findings challenge the conventional wisdom that such states are linked to nonzero topological charge in skyrmion lattices, offering a new perspective in topological magnonics. To facilitate experimental validation, we propose two methods for preparing the skyrmionium lattice and calculate the induced magnon thermal Hall conductivity, which is a key indicator in transport measurements. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13445 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13445v1 Announce Type: new Abstract: Van der Waals heterostructures made from atomically thin transition metal dichalcogenides (TMD) and graphene have emerged as a building block for optoelectronic devices. Such systems are also uniquely poised to investigate interfacial coupling as well as photoinduced charge and energy transfer in the 2D limit. Recent works have revealed efficient photoluminescence quenching and picosecond transfer in TMD/graphene heterostructures. However, key questions regarding the transfer mechanisms remain. Here, employing time-resolved photoluminescence spectroscopy with 1~ps resolution in MoSe$_2$ monolayer directly coupled to a few-layer ``staircase-like'' graphene flake, we consistently observe an exciton transfer time of $\approx 2.5~\mathrm{ps}$ at cryogenic temperature that is marginally affected by the number of graphene layers. Remarkably, exciton transfer vanishes in samples consisting in an MoSe$_2$ monolayer separated from graphene by a thin dielectric spacer of hexagonal boron nitride, as soon as the spacer thickness reaches 1~nm. These results suggest that charge tunnelling processes govern exciton dynamics. Other mechanisms mediated the dipolar interactions (F\"orster-type energy transfer) have no measurable impact on bright excitons (with near-zero center of mass momentum) but may accelerate the relaxation of finite momentum ``hot'' excitons, leading to larger photoluminescence quenching than anticipated based on the measurements of the photoluminescence decay rates. Our work provides important insights into charge and energy transfer in van der Waals materials with direct implications for energy harvesting and funneling. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13364 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13364v1 Announce Type: new Abstract: Aluminum nitride (AlN)-based thin-film bulk acoustic wave resonators (FBARs) are promising compact platforms for 6G communications and quantum memory hardware, enabled by their integrable acoustic modes with high quality factors. However, temperature-dependent acoustic dissipation ultimately limits device performance. In this work, we fabricated a 16 GHz epitaxial AlN FBAR as a test platform, performed small-signal RF measurements from 6.5 K to 300 K, and developed a physics-based model to estimate the fundamental quality-factor limits of FBARs to cryogenic temperatures. The proposed model incorporates both intrinsic and extrinsic loss mechanisms, including an analytical anchor-radiation loss model for bulk acoustic wave resonators, rather than relying solely on finite-element simulations. Measured loaded quality factor (Q) decreases monotonically with temperature, from Qmax of approximately 1589 (Qf=24.79 THz) at 6.5 K to 363 at 294K (Qf=5.66 THz). This trend is consistent with the theoretical limit based on the resonator geometry and the chosen Metal-Insulator-Metal (MIM) stack. To demonstrate the generality of the physics-based framework, we further validate it by benchmarking against a 23 GHz high-overtone bulk acoustic resonator (HBAR) using previously reported data. The validated model provides a practical, transferable framework to interpret Q(T) limits in low-loss resonators by quantifying the temperature-dependent mechanisms that constrain Q, enabling the design of cryogenic microwave filter elements for superconducting quantum hardware. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13337 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13337v1 Announce Type: new Abstract: The nitrogen-vacancy (NV) center in diamond enables optical initialization and readout of its electronic spin, forming the basis of a wide range of quantum sensing and metrology applications. A central challenge in such measurements is the coexistence of two charge states, NV- and NV0: While detection protocols rely on the spin-dependent properties of NV-, fluorescence from NV0 does not carry useful contrast and is typically removed as background, reducing the available signal. Here, we show that the origin of NV0 emission depends strongly on the excitation wavelength in nitrogen-containing diamond. Using ensembles of NV centers with varying nitrogen concentrations, we compare excitation at the NV0 zero-phonon line (ZPL) at 575 nm with the commonly used 532 nm. We find that excitation at 575 nm generates NV0 predominantly through spin-selective tunneling from the excited state of NV- to nearby nitrogen donors, such that the NV0 emission follows the spin polarization of NV-. As a result, the NV0 fluorescence contributes to the measurable spin contrast, allowing the full fluorescence signal to be used for detection. This result opens opportunities for improved sensitivity in NV-based sensing applications. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2603.15534 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.15534v2 Announce Type: replace-cross Abstract: Quantum annealing processors typically control qubits in unison, attenuating quantum fluctuations uniformly until the applied system Hamiltonian is diagonal in the computational basis. This simplifies control requirements, allowing annealing QPUs to scale to much larger sizes than gate-based systems, but constraining the class of available operations. Here we expand the class by performing analog-digital quantum computing in a highly-multiplexed, superconducting quantum annealing processor. This involves evolution under a fixed many-body Hamiltonian that, in the weak-coupling regime, is well-described by an effective XY model, together with arbitrary-basis initialization and measurement via auxiliary qubits. Operationally, this is equivalent to implementing single-qubit gates at the beginning and end of an analog quantum evolution. We demonstrate this capability with several foundational applications: single-qubit and two-qubit coherent oscillations with varying initialization and measurement bases, a multi-qubit quantum walk with fermionic dispersion in line with theory, and Anderson localization in a disordered chain. These experiments open the door to a wide range of new possibilities in quantum computation and simulation, greatly expanding the applications of commercially available quantum annealing processors. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2509.23977 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.23977v2 Announce Type: replace-cross Abstract: Ecological interactions can dramatically alter evolutionary outcomes in complex communities. Yet, the framework of population genetics largely neglects interactions from a species-rich community. Here, we bridge this gap by using dynamical mean-field theory to integrate community ecology into classical population genetics models. We show that ecological interactions result in emergent frequency-dependent selection between parents and mutants, characterized by a single parameter measuring the strength of ecological feedbacks. This result generalizes classical population genetics models to highly diverse communities and enables predictions of mutation outcomes in these eco-evolutionary settings. We derive an analytic expression for fixation probability that extends Kimura's formula and reveals that ecological interactions strongly suppress the fixation of moderately beneficial mutations. This suppression arises because frequency-dependent selection leads to prolonged coexistence between parent and mutant lineages, which acts as a barrier to fixation. The strength of these effects increases with effective population size and the number of open niches in the ecosystem. Our study establishes a framework for integrating ecological interactions into population genetics, showing that evolutionary outcomes can be predicted using simple models even in the presence of complex community feedbacks. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2601.04702 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2601.04702v2 Announce Type: replace Abstract: High-dimensional dynamical systems of interacting degrees of freedom are ubiquitous in the study of complex systems. When the directed interactions are totally uncorrelated, sufficiently strong and non-linear, many of these systems exhibit a chaotic attractor characterized by a positive maximal Lyapunov exponent (MLE). On the contrary, when the interactions are completely symmetric, the dynamics takes the form of a gradient descent on a carefully defined cost function, and it exhibits slow dynamics and aging. In this work, we consider the intermediate case in which the interactions are partially symmetric, with a parameter {\alpha} tuning the degree of non-reciprocity. We show that for any value of {\alpha} for which the corresponding system has non-reciprocal interactions, the dynamics lands on a chaotic attractor. Correspondingly, the MLE is a non-monotonous function of the degree of non-reciprocity. This implies that conservative forcing deriving from the gradient field of a rough energy landscape can make the system more chaotic. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.13843 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13843v1 Announce Type: cross Abstract: We developed a machine learning interatomic potential (MLIP) for Ge-rich GeSbTe alloys of interest for applications in phase change memories embedded in microcontrollers. The MLIP was generated by fitting with a neural network method a large database of energies and forces computed within density functional theory of elemental, binary, stoichiometric and non-stoichiometric ternary alloys in the Ge-Sb-Te phase diagram. The MLIP is demonstrated to be highly transferable to large regions of the phase diagram around the compositions included in the dataset. The MLIP is then exploited to simulate the crystallization with phase separation of three Ge-rich alloys on the Ge-Sb$_2$Te$_3$ and Ge- Ge$_2$Sb$_2$Te$_5$ tie-lines that correspond to the set process of the memory cell. The transformation on the ns time scale and at 600 K, comparable to the operation conditions of the memory, yields crystalline cubic GeTe slightly Sb-doped and amorphous GeSb and Ge. These metastable phases differ from the thermodynamically stable products and form due to kinetics effects on the short time span of the set operation in phase change memories. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.13511 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13511v1 Announce Type: cross Abstract: In many real-world problems, recovering sparse signals from underdetermined linear systems remains a fundamental challenge. Although $\ell_1$ norm minimization is widely used, it suffers from estimation bias that prevents it from reaching the Bayes-optimal reconstruction limit. Nonconvex alternatives, such as the log-sum penalty, have been proposed to promote stronger sparsity. However, maintaining their algorithmic stability is challenging. To address this challenge, we introduce an adaptive smoothing strategy within an approximate message passing framework to mitigate algorithmic instability. Furthermore, we evaluate the typical exact-recovery threshold for Gaussian measurement matrices using the replica method and state evolution. The results indicate that the adaptive method achieves exact recovery over a broader region than $\ell_1$ norm minimization, although metastable states hinder reaching the information-theoretic limit. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.13161 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13161v1 Announce Type: new Abstract: The superconducting transition temperature $T_c$ of the two-dimensional attractive Hubbard model is computed in the vicinity of both ordinary (logarithmic) and higher-order (power-law) Van Hove singularities using determinant quantum Monte Carlo simulations. For interaction strengths $|U| \lesssim W/3$, where $W$ is the electronic bandwidth, $T_c$ is enhanced in the neighborhood of the Van Hove point, albeit more weakly than expected from weak-coupling BCS theory. Enhancing the Van Hove singularity from logarithmic to power-law yields only a minor additional enhancement of $T_c$. For $|U| \gtrsim W/3$, the maximum $T_c$ shifts away from the Van Hove point and instead occurs at a density unrelated to any features in the non-interacting density of states, consistent with a strong-coupling interpretation. We find that the maximal $T_c$ in the model is achieved at intermediate $U$ and at a density away from the Van Hove point. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2512.09994 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2512.09994v2 Announce Type: replace Abstract: Experiments show that the Weyl semimetal PtBi$_2$ hosts unconventional superconductivity in its topological surface states. Hence, the material is a candidate for intrinsic topological superconductivity. Measurements indicate nodal gaps in the center of the Fermi arcs. We derive that anisotropic electron-phonon coupling on Weyl semimetal surfaces, combined with statically screened Coulomb repulsion, is a microscopic mechanism for this nodal pairing. The dominant solution of the linearized gap equation shows nodal gaps when the surface state bandwidth is comparable to the maximum phonon energy, as is the case in PtBi$_2$. We further predict that if the screening of Coulomb interaction on the surface is enhanced by Coulomb engineering, the superconducting gap becomes nodeless, and the critical temperature increases. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.14022 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14022v1 Announce Type: new Abstract: The current-driven resistive transition is central to superconducting single-photon detectors, transition-edge sensors, and fluxonic devices. Depending on sample uniformity, dimensions, and heat removal, it can be driven by phase-slip events, flux-flow instabilities (FFI), or normal-domain formation. Here, we investigate the influence of two types of microstructural defects on vortex dynamics in MgB$_2$ films: columnar growth in textured films and buffer-layer roughness in single-crystal films. The current-voltage ($I$-$V$) curves measured at $T \approx 0.25 T_\mathrm{c}$ for both films exhibit multiple steps. Time-dependent Ginzburg-Landau simulations reproduce the major features of the experimental $I$-$V$ curves and suggest that the resistive transitions for both films are mediated by the formation and growth of normal domains rather than FFI. The single-crystal film with buffer-layer roughness exhibits superconductivity breakdown at higher currents and pinning activation energies approximately twice those of the textured film, along with more pronounced multi-step features in the $I$-$V$ curves. These features are attributed to the combination of stronger pinning induced by lateral variations of the superconducting order parameter along the MgO buffer layer and its lower thermal boundary resistance. Our results show that both the film microstructure and the film-buffer interface are critical for the resistive transition, offering insights for superconducting devices requiring controlled dissipation at high transport currents. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2601.20189 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2601.20189v2 Announce Type: replace Abstract: Several ground state properties of the square-lattice $S=1/2$ Heisenberg antiferromagnet are computed (the energy, order parameter, spin stiffness, spinwave velocity, long-wavelength susceptibility, and staggered susceptibility) using extensive quantum Monte Carlo simulations with the stochastic series expansion method. Moderately sized lattices are studied at temperatures $T$ sufficiently low to realize the $T \to 0$ limit. Results for periodic $L\times L$ lattices with $L \in [6,96]$ are tabulated versus $L$ and extrapolations to infinite system size are carried out. The extrapolated ground state energy density is $e_0=-0.669441857(7)$, which represents an improvement in precision of three orders of magnitude over the previously best result. The leading and subleading finite-size corrections to $e_0$ are in full quantitative agreement with predictions from chiral perturbation theory, thus further supporting the soundness of both the extrapolations and the theory. The extrapolated sublattice magnetization is $m_s=0.307447(2)$, which agrees well with previous estimates but with a much smaller statistical error. The coefficient of the linear in $L^{-1}$ correction to $m^2_s$ agrees with the value from chiral perturbation theory and the presence of a factor $\ln^\gamma(L)$ in the second-order correction is also confirmed, with the previously not known value of the exponent being $\gamma = 0.82(4)$. The finite-size corrections to the staggered susceptibility point to logarithmic corrections also in this quantity. To facilitate benchmarking of methods for which periodic boundary conditions are challenging, results for systems with open and cylindrical boundaries are also listed and their spatially inhomogeneous order parameters are analyzed. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2512.13786 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2512.13786v2 Announce Type: replace Abstract: Dynamical control of quantum matter is a challenging, yet promising direction for probing strongly correlated states. Motivated by recent experiments in twisted MoTe$_2$ that demonstrated optical control of magnetization, we propose a protocol for probing magnetization dynamics in flat-band ferromagnets. We investigate the nucleation and dynamical growth of magnetic bubbles prepared on top of a false vaccum in both itinerant ferromagnets and spin-polarized Chern insulators. For ferromagnetic metals, we emphasize the crucial role of a non-trivial quantum geometry in the magnetization dynamics, which in turn also provides a probe for the quantum metric. Furthermore, for quantum Hall ferromagnets, we show how properties of chiral edge modes localized at domain-wall boundaries can be dynamically accessed. Our work demonstrates the potential for nonequilibrium protocols to control and probe strongly correlated phases, with particular relevance for twisted MoTe$_2$ and graphene-based flat-band ferromagnets. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2510.25994 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2510.25994v2 Announce Type: replace Abstract: We generalize the Hyperbolic Fracton Model from the $\{5,4\}$ tessellation to generic tessellations, and investigate its core properties: subsystem symmetries, fracton mobility, and holographic correspondence. While the model on the original tessellation has features reminiscent of the flat-space lattice cases, the generalized tessellations exhibit a far richer and more intricate structure. The ground-state degeneracy and subsystem symmetries are generated recursively layer-by-layer, through the inflation rule, but without a simple, uniform pattern. The fracton excitations follow exponential-in-distance and algebraic-in-lattice-size growing patterns when moving outward, and depend sensitively to the tessellation geometry, differing qualitatively from both type-I or type-II fracton model on flat lattices. Despite this increased complexity, the hallmark holographic features -- subregion duality via Rindler reconstruction, the Ryu-Takayanagi formula for mutual information, and effective black hole entropy scaling with horizon area -- remain valid. These results demonstrate that the holographic correspondence in fracton models persists in generic tessellations, and provide a natural platform to explore more intricate subsystem symmetries and fracton physics. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2509.20337 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.20337v2 Announce Type: replace Abstract: As a consequence of their spin-orbit entangled ground state, many $5d^{5}$ iridate materials display a peculiar double peak structure in optical transport quantities, such as absorption and conductivity. Their common interpretation is based on the presence of Hubbard subbands in the half-filled $j_{\mathrm{eff}}=1/2$ manifold. Herein, we challenge this picture, proposing a scenario based on the presence of spin-polaron (SP) quasiparticles, and assigning a dominant SP character to the first peak. We illustrate it by taking the materials Ba$_2$IrO$_4$ and Sr$_2$IrO$_4$ as paradigmatic examples, which we investigate within the dynamical mean-field theory and the self-consistent Born approximation. Both theories reproduce nontrivial features revealed by angle-resolved photoemission spectroscopy and optical transport measurements, supporting our interpretation. In the case of Sr$_2$IrO$_4$, we show how the SP scenario survives in the low-doped regime. Similar optical transport fingerprints are expected to be found in the wider class of $5d^5$ iridates and more generally in strongly correlated antiferromagnetic regimes, such as those found in cuprates. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2509.19764 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.19764v5 Announce Type: replace Abstract: Moir\'e superlattices host a rich variety of correlated topological states, including interaction-driven integer and fractional Chern insulators. A common approach to study interacting ground states at integer fillings is the Hartree-Fock mean-field method. However, this method neglects dynamical correlations, which often leads to an overestimation of spontaneous symmetry breaking and fails to provide quantitative descriptions of single-particle excitations. This work introduces a general many-body perturbation framework for moir\'e systems, combining all-band Hartree-Fock calculations with $GW$ quasiparticle corrections and random phase approximation (RPA) correlation energies. We apply this framework to hexagonal boron nitride aligned rhombohedral pentalayer graphene and magic-angle twisted bilayer graphene (MATBG). We show that incorporating RPA correlation energy and $GW$ self-energy corrections yields phase diagrams and single-particle spectra that quantitatively align with experimental measurements for both systems. Particularly, the ground state at charge neutrality of MATBG is predicted to be a nematic metal, which is stabilized over Kramers intervalley coherent insulator due to lower correlation energy. Our versatile framework provides a systematic beyond-mean-field approach applicable to generic moir\'e systems. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2504.03324 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2504.03324v3 Announce Type: replace Abstract: We demonstrate the existence of an unconventional pairing state in photodoped Mott insulators on ladder and quasi-two-dimensional geometries, characterized by quasi-long-range doublon-holon correlations that signal Mott exciton condensation. The doublon-holon pairing exhibits correlations of $d$-wave-like symmetry, reminiscent of superconducting pairing in chemically doped Mott insulators. By constructing the phase diagram, using density matrix renormalization group, we reveal that the doublon-holon pairing state in the photodoped ladder emerges between the spin-singlet, charge-density-wave, and $\eta$-pairing phases. Our study suggests that the interplay of charge, spin, and $\eta$-spin degrees of freedom can give rise to exotic quantum many-body states in photodoped Mott insulators. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2502.04814 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2502.04814v2 Announce Type: replace Abstract: CeTe$_3$ is a 2--dimensional (2D) Van der Waals (VdW) material with incommensurate charge density waves (CDW), extremely high transition temperature ($T_{CDW}$) and a large momentum--dependent CDW gap that leaves a significant portion of the Fermi surface intact. It is also considered to be a weak Kondo system, a property unexpected for a material with incommensurate CDW, where each atomic site is slightly different. Here, we study the properties of the CDW state in several RTe$_3$ (R is rare earth) materials and examine the hybridization of itinerant states with the localized Ce $4f$ multiplet in CeTe$_3$ by using angle resolved photoemission spectroscopy (ARPES). We find that the renormalization of the itinerant states originating from the hybridization with the deeper localized $4f$ states at $-260$ meV is $k-$dependent and extends to the Fermi level. As these localized states are far from the Fermi level, the observed hybridization affects the effective masses only marginally and does not lead to heavy fermions. However, since the same renormalizing mechanism normally leads to the heavy fermion physics when the localized $4f$ states are near the Fermi level, our observation of its strong $k-$dependence suggests that this could be the reason for discrepancy between the heavy masses in specific heat and light ones in Shubnikov de Haas oscillations, often observed in heavy fermions. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14115 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14115v1 Announce Type: cross Abstract: In this paper, we develop a class of antisymmetrized geminal power configuration interaction (AGP-CI) wave functions that extend the AGP framework by incorporating inter-geminal correlations through a CI expansion. To make these wavefunctions computationally tractable, we evaluate them by rewriting the AGP-CI ansatz as a linear combination of AGPs (LC-AGP), for which overlaps and Hamiltonian matrix elements can be computed with standard AGP machinery. Motivated by border-rank decompositions, we further reorganize this ansatz into a compact linear combination of AGPs depending on a small deformation parameter $\tau$, which controls how closely the truncated expansion approximates the full AGP-CI state. Benchmark applications to the Hubbard model and to the small molecules H$_2$O and N$_2$ demonstrate that the proposed wavefunctions achieve consistently high accuracy and outperform the LC-AGP, particularly for systems with more electrons and in strongly correlated regimes. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14045 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14045v1 Announce Type: cross Abstract: The supercurrent diode effect (SDE), characterized by unequal critical currents in opposite directions, has been observed with or without magnetic fields, yet mechanisms enabling zero-field SDE without explicit symmetry breaking remain underexplored. Here we investigate a Josephson junction with strong electron-electron interaction modeled by a Hubbard $U$ term and an odd number of electrons. We find that strong correlations induce spontaneous breaking of time-reversal and mirror symmetries, forming a $\varphi$-junction with degenerate energy minima at $\pm\varphi$, resulting in zero-field Josephson diode effect (JDE) without magnetic order. Spin-orbit coupling breaks SU(2) symmetry but does not determine diode polarity, contrasting with magneto-chiral mechanisms. We further show that applying a tiny Zeeman field enables controllable JDE with sizable efficiency due to the enhancement by the strong magnetic correlation, and the JDE strength peaks when the field induces a level-crossing transition. These findings establish strong electron correlation as a distinct mechanism for nonreciprocal superconducting transport, broadening the understanding of SDE origins. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14146 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14146v1 Announce Type: new Abstract: Investigating the interplay among topology and electron-electron interactions is an intriguing research quest which has recently gathered steam across the community of condensed-matter physics. In the present work, we study the fate of a three-dimensional Berry-dipole semimetal, lying at the topological quantum critical point separating a Hopf insulator from a trivial insulator, in the presence of long-range Coulomb interactions. Utilizing large-$N_f$ analysis at three spatial dimensions and an $\epsilon$-expansion within the renormalization-group scheme, we uncover the emergence of a spatially \textit{anisotropic} non-Fermi liquid with enhanced Berry-dipole moment. We further derive the corresponding scaling relations of certain physical observables as functions of the probed energy and temperature scale, and we provide a simple observational criterion for distinguishing the onset of the topological anisotropic non-Fermi liquid from a Berry-dipole semimetal. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14012 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14012v1 Announce Type: new Abstract: The novel kagome family RTi3Bi4 (R: rare-earth) offers a unique platform for exploring distinctive physical phenomena such as anisotropy, spin density wave, and anomalous Hall effect. In particular, the magnetic frustration and behavior of magnetic anisotropy in antiferromagnetic (AFM) kagome materials are of great interest for the fundamental studies and hold promise for next-generation device applications. Here, we report a tunable bifurcation of magnetic anisotropic and bi-oriented AFM order observed in the quasi-1D kagome antiferromagnet GdTi3Bi4. The magnetic domain evolutions during two plateau transition processes are directly visualized, unveiling a pronounced in-plane anisotropy along the a-axis. Temperature-dependent characterization reveals a bifurcation transition of anisotropy at approximately 2 K, where the a-axis anisotropy splits into two special orientations, revealing a hidden bi-oriented in-plane AFM order deviating from the high-symmetry direction by 7 degree. More intriguingly, the characteristics of the bifurcated anisotropy are clearly illustrated through vector magnetic field modulation, revealing three distinct in-plane domain phases in the transverse magnetic field phase diagram. Our results not only provide valuable insights into the tunable bifurcation of magnetic anisotropic in GdTi3Bi4, but also pave a novel pathway for AFM spintronics development. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.14002 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14002v1 Announce Type: new Abstract: Charge density waves (CDWs) are a widespread collective electronic order in quantum materials, furnishing key insights into symmetry breaking and competing phases. However, their dynamic control with external fields remains a pivotal challenge. Here, we report deterministic and hysteretic switching of unidirectional CDW orientation via in-plane magnetic field rotation in magnetic kagome metal GdTi3Bi4. Atomically resolved spectroscopy shows two types of 3a0*1a0 CDW domains, Q1 and Q2 oriented 60 degree apart along two distinct crystallographic directions and separated by atomically sharp domain walls. Rotating the magnetic field drives reversible transitions between these CDW configurations, exhibiting a robust C2-symmetric phase diagram with pronounced hysteresis. This hysteretic switching is mediated by a field-dependent reorientation of underlying antiferromagnetic spins, revealing a tunable energy landscape with stable and metastable states and modulates the electronic charge order via spin-lattice coupling. Our findings not only demonstrate the switching of CDW configurations by in-plane magnetic field but also reveal the mechanism of coupling between CDW and magnetic fields, offering new insights into CDW manipulation and versatile platform for developing a spin-mediated multistate spin-charge coupling memory and programmable quantum devices. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13958 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13958v1 Announce Type: new Abstract: Many-body effects in condensed matter yield novel quantum states when the electronic density of states is enhanced. A vivid example is flat bands, which suppress kinetic energy and let interactions dominate, when they are filled with an integer number of electrons in moire systems. Yet flat bands and commensurate fillings are not the only conditions for correlated phenomena. Situations may occur where the band structure develops locally enhanced density of states, leading to strong correlations even at non-integer fillings, although such cases often yield pseudogaps that make detection elusive. Here we demonstrate that small-angle twisted monolayer-bilayer graphene combines moire-induced global flat band and additional local band flattening. Their coexistence allows direct comparison of correlated effects. The global route stabilizes commensurate states, while the local mechanism produces nearly flat bands, lifting degeneracy and generating symmetry breaking at non-integer fillings, yet without opening a global gap. Because there is no global gapped signature, the system remains metallic, but the effect reveals itself in anomalous Hall responses, signaling time-reversal symmetry breaking and valley polarization. Our results demonstrate dual-flatness as a guiding principle, extending moire physics beyond commensurate fillings and identifying topological transport as a probe of gapless correlated metals. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13864 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13864v1 Announce Type: new Abstract: Structural disorder in the magnetically frustrated pyrochlore system leads to intriguing magnetic states. We present the thermodynamic behavior and short range magnetic correlations in Tb$_{2}$Zr$_{2}$O$_{7}$ and Tb$_{2}$Zr$_{1.5}$Ti$_{0.5}$O$_{7}$ compounds. The parent compound Tb$_{2}$Zr$_{2}$O$_{7}$ has defect fluorite structure, which evolves toward the pyrochlore phase on Ti doping at Zr site. There is no long range magnetic order down to 0.4 K, and a magnetic field dependent spin freezing evolves below 1.25 K and 1.05 K for the parent and doped compounds, respectively. The ac susceptibility measurements indicate slow spin relaxation process below 20 K in these compounds. Inelastic neutron scattering reveals broad diffuse scattering, indicative of short range correlations at low temperature, owing to local structural distortions and persistent spin fluctuations. These results suggest a correlated, disorder influenced magnetic state in Tb$_{2}$Zr$_{2}$O$_{7}$, Tb$_{2}$Zr$_{1.5}$Ti$_{0.5}$O$_{7}$ compounds. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13751 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13751v1 Announce Type: new Abstract: On the textbook example of an isolated antiferromagnetic Heisenberg dimer, we demonstrate that the magnetic form factor and the magnetic electron density distribution can be extracted from the momentum-dependence of the inelastic neutron scattering (INS) intensity of a magnetic excitation. We measure the three-dimensional (3D) magnetic structure factor of the singlet-to-triplet excitation in Cu(II) acetate monohydrate with INS. Using a minimal parametrization of the magnetic electron density, we deduce the real-space density of the spin-entangled electrons and the transfer of magnetic electron density between metal and ligand atoms from the experimental data. Density functional theory (DFT) calculations reproduce the measured structure factor quantitatively, providing a direct validation of DFT broken-symmetry spin densities against full 3D INS data. The quantitative agreement between experiment, parametrization, and theory establishes a robust framework for determining magnetic form factors and the magnetic electron density in a broad range of magnetic materials and demonstrates INS as a probe of the envelope of spatial electronic wavefunctions. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13651 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13651v1 Announce Type: new Abstract: We have performed detailed temperature-dependent study of optical f-f transitions of the Yb3+ ions in h-YbMnO3 by means of Fourier-transform spectroscopy. The splitting of the ground Kramers doublet as a function of temperature, D0(T), for the Yb3+ ion at 4b site was determined. The D0(T) function follows the dynamics of the manganese magnetic moment below TN = 87 K, indicating, that the ytterbium subsystem is magnetized by the magnetic field generated by an ordered manganese subsystem, which is consistent with the results of previous studies. Excitation of the upper component of the split ground doublet plays a significant role in low-temperature dynamics of the h-YbMnO3 crystal. Using the D0(T) function we calculated the temperature behavior of the of the Yb(4b) magnetic moment: it is in clear agreement with the neutron data [Phys. Rev. B 98, 134413, 2018]. The calculated contribution of Yb(4b) to heat capacity definitely explains the origin of the Schottky anomaly in the CP(T) dependence. A scenario for phase transitions in h-YbMnO3 is proposed in which the energy gain in the ytterbium system plays a key role. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13576 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13576v1 Announce Type: new Abstract: We report on new results of 9Be nuclear magnetic resonance (NMR) measurements conducted on a single crystal of the heavy fermion superconductor UBe13. Our previous 2007 study [J. Phys. Soc. Jpn. 76 204705 (2007)] determined NMR and electric field gradient (EFG) parameters that successfully reproduced the NMR spectra at low magnetic fields. However, these parameters did not accurately describe the angular dependence of the NMR spectra at high magnetic fields. To address this discrepancy, we have now performed a more comprehensive investigation, measuring the magnetic field dependence of the 9Be-NMR spectra across a field range of 0.5 T to 8 T, as well as the magnetic field angle dependence at 0.5 T and 6 T. Through detailed simulations that take into account the non-symmorphic space group of UBe13, we have determined a new set of parameters capable of reproducing the complex NMR line profiles observed at high magnetic fields. Notably, our analysis reveals the significant influence of classical dipolar fields. A comparison between the Knight shift (KS) and the classical dipolar shift provides microscopic supporting evidence for the nature of an itinerant-localized duality in UBe13. Furthermore, the magnetic field dependence of the KS exhibits anomalies around 6 T, suggesting a reconstruction of a part of the multiple Fermi surfaces in the high magnetic field region. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13553 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13553v1 Announce Type: new Abstract: As a unique kagome superconductor displaying clear signatures of strong electronic correlations, CsCr$_3$Sb$_5$ has drawn much attention. Its rich temperature-pressure phase diagram features intertwined orders including pressure-induced superconductivity and two density-wave-like phases, making it an outstanding platform to explore the complex coexistence and competition of multiple quantum orders. At around 30 K, which we designate as $T_3$, a possible anomaly manifesting as a hump in the resistivity has been observed, yet its nature remains largely unexplored due to limited supporting evidence from other probes. Here, we conducted systematic magnetotransport experiments under hydrostatic pressure to investigate the nature of this anomaly. Our results reveal an abundance of intriguing magnetotransport signatures below $T_3$, including a non-trivial temperature dependence of the Hall coefficient, multi-band characteristics, and pressure-enhanced anomalous-Hall-like effect. These signatures bear resemblance to those observed in the charge-density-wave state in the sister compound CsV$_3$Sb$_5$. These findings suggest the possibility of an additional, exotic electronic order in CsCr$_3$Sb$_5$, calling for further detailed investigations. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13093 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13093v1 Announce Type: new Abstract: Here a finite-Lieb-lattice quantum computing circuit consisting of spin-1/2 quantum bits (qubits) and triplet couplers is designed. Important gradient - quantum entanglement - is analysed. This type of design could be realised in a vast range of molecules containing multiple radicals, in which the communications among qubits are controlled by the optically driven triplets. The von Neumann entanglement entropy, reduced density matrices, and spin-spin correlations were computed using tensor-network methods by varying the magnetic anisotropy and external magnetic field. This work uncovers the rich entanglement patterns, quantum phase transitions, and tunable spin coherence in this mixed spin system, designed for molecular spin-based quantum computing. These findings have important implications for triplet-mediated molecular self-assembly quantum computing circuit, especially for the entangling gate based on molecules. This work would provide a theoretical cornerstone for the experimental realisation of scalable molecule-based quantum computing circuits. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2603.02328 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.02328v2 Announce Type: replace-cross Abstract: Local decoders provide a promising approach to real-time quantum error-correction by replacing centralized classical decoding, with significant hardware constraints, by a fully distributed architecture based on a simple, local update rule. We propose a new local decoder for Kitaev's toric code: the 2D signal-rule, that interprets odd parity stabilizer measurements as defects, attracted to each other via the exchange of binary signals. We present numerical evidence of exponential suppression of the logical error rate with system size below a threshold, under a phenomenological noise model with data and measurement errors at each iteration. The construction achieves a significantly improved threshold and optimal finite-size scaling relative to hierarchical schemes. It also provides a lightweight alternative to windowed local decoder constructions while maintaining strong performance, thus enabling a streamlined architecture for a two-dimensional local quantum memory. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2510.15766 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2510.15766v3 Announce Type: replace-cross Abstract: We introduce the subdimensional entanglement entropy (SEE), defined on subdimensional entanglement subsystems (SESs) embedded in the bulk, as an entanglement-based probe of how geometry and topology jointly shape universal properties of quantum matter. By varying the dimension, geometry, and topology of the SES, we show that the subleading term of SEE exhibits sharply distinct responses in different phases, including cluster states, $\mathbb{Z}_q$ topological orders, and fracton orders. Treating the reduced density matrix of an SES as a many-body mixed state supported on the SES manifold, we further establish a general correspondence between bulk stabilizers and mixed-state symmetries on SESs, separating them into strong and weak classes, and use it to identify strong-to-weak spontaneous symmetry breaking within SESs. Finally, for SESs with nontrivial SEE, we show that weak symmetries act as transparent patch operators of the corresponding strong symmetries. This motivates the notion of transparent composite symmetry, which remains robust under finite-depth quantum circuits that preserve SEE, and implies that each $D$-dimensional SES holographically encodes a $(D+1)$-dimensional topological order. These results establish SEE not only as a sharp probe of geometric-topological response, but also as a route from bulk pure-state entanglement to mixed-state symmetry and holography on subdimensional manifolds. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2507.01064 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2507.01064v2 Announce Type: replace-cross Abstract: Signal detection in high dimensions is a critical challenge in data science. While standard methods based on random matrix theory provide sharp detection thresholds for finite-rank perturbations, such as the known Baik-Ben Arous-P\'ech\'e (BBP) transition, they are often insufficient for realistic data exhibiting nearly continuous (extensive-rank) signal distributions that merge with the noise bulk. In this regime, typically associated with real-world scenarios such as images for computer vision tasks, the signal does not manifest as a clear outlier but as a deformation of the spectral density's geometry. We use the functional renormalisation group (FRG) framework to probe these subtle spectral deformations. Treating the empirical spectrum as an effective field theory, we define a scale-dependent "canonical dimension" that acts as a sensitive order parameter for the spectral geometry. We show that this dimension undergoes a sharp crossover, interpreted as a "dimensional phase transition", at signal-to-noise ratios significantly lower than the standard BBP threshold. This dimensional instability is shown to correlate with a spontaneous symmetry breaking in the effective potential and a deviation of eigenvector statistics from the universal Porter-Thomas distribution, confirming the consistency of the method. Such behaviour aligns with recent theoretical results on the "extensive spike model", where signal information persists inside the noise bulk before any spectral gap opens. We validate our approach on realistic datasets, demonstrating that the FRG flow consistently detects the onset of this bulk deformation. Finally, we explore a formalisation of this methodology for analysing nearly continuous spectra, proposing a heuristic criterion for signal detection and a method to estimate the number of independent noise components based on the stability of these canonical dimensions. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2506.02888 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2506.02888v2 Announce Type: replace-cross Abstract: We present a universal thermodynamic framework for quantum systems that may be strongly coupled to thermal environments. Unlike previous approaches, our method enables a clear definition of thermostatic properties while preserving the same gauge freedoms as in the standard weak-coupling regime and retaining the von Neumann expression for thermodynamic entropy. Furthermore, it provides a formulation of general first and second laws using only variables accessible through microscopic control of the system, thereby enhancing experimental feasibility. We validate the framework by applying it to a paradigmatic model of strong coupling with a structured bosonic reservoir. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2503.14645 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2503.14645v2 Announce Type: replace-cross Abstract: We introduce parallel-sequential (PS) circuits, a family of quantum circuit layouts that interpolate between brickwall and sequential circuits, which introduces control parameters governing a trade-off between the amount of entanglement and the maximum correlation range they can express. We provide numerical evidence that PS circuits can efficiently prepare many-body ground states in one dimension. On noisy devices, characterized through both idling errors and two-qubit gate errors, we show that in a wide parameter regime, PS circuits outperform brickwall, sequential, and the log-depth circuits from [Malz, Styliaris, Wei, Cirac, PRL 132, 040404 (2024)]. Additionally, we demonstrate that properly chosen noisy random PS circuits suppress error proliferation and, when employed as a variational ansatz, exhibit superior trainability. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2503.07720 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2503.07720v2 Announce Type: replace-cross Abstract: We introduce a variational algorithm based on the quantum alternating operator ansatz (QAOA) for the approximate solution of computationally hard counting problems. Our algorithm, dubbed VQCount, is based on the equivalence between random sampling and approximate counting and employs QAOA as a solution sampler. We first prove that VQCount improves upon previous work by reducing exponentially the number of samples needed to obtain an approximation within an arbitrary small multiplicative factor of the exact count. Using tensor network simulations, we then study the typical performance of VQCount with shallow circuits on synthetic instances of two #P-hard problems, positive #NAE3SAT and positive #1-in-3SAT. We employ the original quantum approximate optimization algorithm version of QAOA, as well as the Grover-mixer variant which guarantees a uniform solution probability distribution. We observe a tradeoff between QAOA success probability and sampling uniformity, which we exploit to achieve an empirical efficiency gain over both naive rejection sampling and Grover-based quantum counting. Our results highlight the potential and limitations of variational algorithms for approximate counting. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2108.10000 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2108.10000v2 Announce Type: replace-cross Abstract: Cancer cell populations often exhibit remarkably similar growth laws despite their heterogeneity. Explanations of universal cell population growth remain partly unresolved to this day. Here, we present a growth-law unification by investigating the connection between microscopic assumptions and the expected contact inhibition, which leads to five classical tumor growth laws: exponential, radial growth, fractal growth, generalized logistic, and Gompertzian growth. All five can be seen as manifestations of a single microscopic model. Agent-based simulations substantiate our theory, and we can explain differences in growth curves in experimental data from em in vitro cancer cell population growth. Thus, our framework offers a possible explanation for many mean-field laws used to empirically capture seemingly unrelated cancer or microbial growth dynamics. Our results highlight that the interplay between contact inhibition and other assumptions (e.g., well-mixed) can influence our quantitative understanding of how cancer cells grow and, in turn, how they may interact. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.10536 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.10536v2 Announce Type: replace Abstract: Using nonequilibrium and equilibrium molecular dynamics simulations, we investigate heat conduction in a momentum-conserving mesoscopic fluid modeled by multiparticle collision dynamics. Across quasi-two-dimensional (q-2D) to three-dimensional (3D) systems, we identify three distinct transport regimes: (i) a \emph{ballistic regime}, where thermal conductivity scales linearly with system size ($\kappa \sim L$) and the total heat current autocorrelation function $C(t)$ remains constant; (ii)~a \emph{kinetic regime}, characterized by size-independent $\kappa$ and exponentially decaying $C(t)$, demonstrating that normal heat conduction dominated by kinetic effects is far more ubiquitous than previously observed in 1D systems; and (iii)~a \emph{hydrodynamic regime}, where the q-2D system exhibits logarithmically divergent conductivity ($ \kappa \sim \ln L $ ) with $ C(t) \sim t^{-1} $ , while the 3D system displays finite $ \kappa $ and $ C(t) \sim t^{-3/2} $. Our results, observed in the hydrodynamic regime, quantitatively validate the scaling predictions for heat transport and reveal a clear dimensional crossover -- from 2D-like anomalous transport to 3D Fourier behavior. These results lay a foundation for understanding thermal transport in q-2D to 3D systems and have practical implications for the design of micro- and nanoscale thermal devices. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2602.16060 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2602.16060v2 Announce Type: replace Abstract: In this study, a recently introduced order parameter called the weighted coordination number (WCN) was used to investigate the liquid-liquid (LL) phase separation, indicating temperature-dependent coarsening of the LL interface as a possible mechanism for the glass transition. A well-established glass-forming Kob-Andersen binary Lennard-Jones system was used in this study. The gas-liquid binodal line was reconstructed using WCNs, and the same approach was extended to study the liquid-liquid binodal line. Systems of various densities are instantaneously quenched from high to low temperatures where liquid-liquid separation is observed. The densities and composition of each liquid state were used to verify the level rule, along with the density and pressure profiles, demonstrating the local equilibrium of liquid-liquid phase separation. The transition from the liquid-liquid phase separation in the supercooled region to the glass transition region was modeled by adopting a Markov Network Model to estimate the temperature-dependent viscosity using liquid-liquid interfacial information from the classification. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2601.14387 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2601.14387v2 Announce Type: replace Abstract: Energy costs of information processing are growing exponentially. Bit erasure is a key problem in this energy-information nexus, and a number of seminal relationships have been deduced regarding the relationship between thermodynamic costs and memory storage. To continue making progress in the modern era, however, requires confronting thermodynamic costs in realistic physical systems which operate away from equilibrium. Here, we explore the thermodynamic costs of bit erasure in a complementary metal oxide semiconductor model of two types of random access memory. We find dynamic random access memory dissipates the least amount of energy when operated in the quasistatic limit, where errors are also minimized. By contrast, static random access memory is most efficiently operated in finite time due to the energy required to maintain the state of the bit. We demonstrate a numerically robust optimization scheme using mean field theory and automatic differentiation, finding optimal protocols compatible with electrical engineering insights. These results provide a framework for operating realistic circuits in thermodynamically advantageous ways. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2510.25454 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2510.25454v3 Announce Type: replace Abstract: We study the role of fluctuations in particle systems modeled by Dean-Kawasaki-type equations, which describe the evolution of particle densities in systems with Brownian motion. By comparing microscopic simulations, stochastic partial differential equations, and their deterministic counterparts, we analyze four models of increasing complexity. Our results identify macroscopic quantities that can be altered by the conserved multiplicative noise that typically appears in the Dean-Kawasaki-type description. We find that this noise enhances front propagation speed in systems with density-dependent diffusivity, accelerates the onset of pattern formation in particle systems with nonlocal interactions, and reduces hysteresis in systems interacting via repulsive forces. In some cases, it accelerates transitions or induces structures absent in deterministic models. These findings illustrate that (conservative) fluctuations can have constructive and nontrivial effects, emphasizing the importance of stochastic modeling in understanding collective particle dynamics. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2509.24985 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.24985v2 Announce Type: replace Abstract: In complex ecological communities, species may self-organize into clusters or clumps where highly similar species can coexist. The emergence of such species clusters can be captured by the interplay between neutral and niche theories. Based on the generalized Lotka-Volterra model of competition, we propose a minimal model for ecological communities in which the steady states contain self-organized clusters. In this model, species compete only with their neighbors in niche space through a common interaction strength. Unlike many previous theories, this model does not rely on random heterogeneity in interactions. Even in this minimal model where only the common interaction strength is varied, we find an exponentially large set of states that exhibit a rich variety of cluster patterns with different sizes and combinations. There are sharp phase transitions into the formation of clusters. There are also multiple phase transitions between different sets of possible cluster patterns, many of which accumulate near a small number of critical points. We analyze this phase structure using both numerical and analytical methods. In addition, the special case with only nearest neighbor interactions is exactly solvable using the method of transfer matrices from statistical mechanics. We analyze the critical behavior of these systems. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.14110 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14110v1 Announce Type: cross Abstract: We derive deterministic equations for the evolution of non-Gaussian fluctuations in relativistic stochastic hydrodynamics. This is achieved by defining the average local Landau frame and corresponding fluctuating hydrodynamic variables. Fully nonlinear stochastic hydrodynamics is expressed in a unified multi-component matrix form. A novel relativistic formalism, also manifestly covariant under SO(3) rotations of the local spatial basis in the average local Landau frame, is introduced. The equations describe correlators of all hydrodynamic variables, including fluctuating velocity (or momentum density) -- a nontrivial problem in relativistic hydrodynamics. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13923 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13923v1 Announce Type: cross Abstract: We present a Krylov space based theoretical framework for modeling inhomogeneous spin ensembles with arbitrary distributions of spin frequencies and couplings. The framework is then used to asymptotically large spin ensemble. In the single-excitation subspace, the Krylov construction allows for to derive exact expressions for the Lieb-Robinson velocity and quantum speed limit, and figure of merit such as Krylov complexity. Our work reveals a strong dependence of the speed of information flow on the statistical distribution of resonance frequencies in the spin ensemble with immediate implications for the design of components for quantum technologies, realized for example with nitrogen vacancy centers, nuclear spins or ultracold atoms. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13615 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13615v1 Announce Type: cross Abstract: In nonlinear systems, small perturbations are conventionally attributed to negligible nonlinearity, justifying linear approximations. Here, we uncover a notable exception to this paradigm in an electrokinetic (EK) flow. Using a novel dual frequency excitation scheme with two high frequency AC electric fields ($> 10^{5}$ Hz), we efficiently excite flow perturbations at a difference frequency ($\Delta f$) four orders of magnitude lower. This approach reveals a strong nonlocal energy transfer mechanism mediated purely by the nonlinearity of the electric body force, enabling precise, clean flow control free from electrode polarization artifacts. Unexpectedly, these small, nominally linear velocity and electric conductivity fluctuations exhibit power law spectra. With increasing electric Rayleigh number, the scaling exponents agree quantitatively with predictions for fully developed EK turbulence by the Quad cascade process theory. This observation not only implies multiple flow state transitions even at low excitations, but also indicates that intrinsic nonlinearity regulates perturbations even in the linear regime, necessitating a fundamental re examination of linear approximations in electrohydrodynamics and other nonlinear systems. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13249 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13249v1 Announce Type: cross Abstract: We introduce a simulation technique to compute the free energy difference between two hydrate structures of different stoichiometry connected to a reservoir of gas molecules at a prescribed pressure. The method permits the determination of coexistence parameters for the system when the two hydrate structures have the same number of water molecules $N_w$. The approach is based on performing isobaric Lattice Switch Monte Carlo simulations to measure free energy differences between the hydrate structures when they are either fully occupied by gas molecules, or fully empty. This measurement is combined with thermodynamic integration within an ensemble in which the number of guest molecules $N_g$ can fluctuate under the control of a chemical potential $\mu_g$. We analyze the properties of the resulting constant-$N_w,\mu_g,P,T$ ensemble and show how it can be used to calculate coexistence points via a thermodynamic cycle. Applying the method to argon and methane structures, we find coexistence pressures that are in good agreement overall with the available experimental data. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13172 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13172v1 Announce Type: cross Abstract: We establish a rigorous relation between the thermalization of typical initial states and the dynamics of local operators. We introduce a concept of simple slow operators (SSOs), defined as operators that have a small commutator with the Hamiltonian and have significant small-sized components. We show that if typical initial states (drawn from a low-complexity state ensemble) do not thermalize on timescale $t$, then SSOs must exist that are approximately conserved up to timescale $t$. Equivalently, the absence of SSOs implies that typical initial states thermalize. We establish these results by introducing the concept of an ensemble variance norm of an operator, defined as the typical magnitude of the expectation value of that operator with respect to states in the ensemble. For low-entanglement ensembles, the norm is related to operator sizes, allowing us to establish a direct link between operator growth and thermalization. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.14143 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14143v1 Announce Type: new Abstract: We construct upper bounds on entanglement entropies of many-body quantum states that have fixed energy expectation values with respect to geometrically local Hamiltonians. Our focus is on entanglement entropies of subsystems that make up approximately half of the full system. The upper bound on the von Neumann entanglement entropy is half the sum of the thermal entropies of two fictitious systems at the same temperature as one another, with an additional area-law contribution in some systems. The effective temperature is chosen such that the sum of the thermal energies of the two fictitious systems matches the constraint on the energy of the state in the original problem; at subextensive energies, this temperature decreases with increasing system size. Our upper bounds on R\'{e}nyi entanglement entropies take an analogous form. As a first application we show that ground-state Schmidt ranks in frustration-free (FF) systems are upper bounded by the ground-state degeneracies of Hamiltonians acting on subsystems. Ground-state von Neumann and R\'{e}nyi entanglement entropies therefore follow an area law when the zero-temperature thermal entropies of subsystems scale with surface areas, rather than with subsystem volumes. This result holds independently of the spectral gap. For physical models of quantum matter, which have well-defined specific heat capacities (and are not necessarily FF), our bounds provide a way to convert this thermodynamic data into constraints on pure-state entanglement at both subextensive and extensive energies. We also show that our upper bounds on half-system entanglement entropies are optimal, up to subleading corrections, in wide varieties of systems. Our results relate physical thermodynamic properties to the structure of many-body Hilbert space at low energies. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13885 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13885v1 Announce Type: new Abstract: We study the role of heterogeneous volatility in a networked wealth dynamics model and its impact on the wealth condensation transition. Extending the Bouchaud--M{\'e}zard framework, we introduce binary volatility in networks and investigate how its configuration affects the effective power-law tail exponent of the wealth distribution. Using a stochastic block model, we control the mixing between volatility groups and show that the effective exponent is governed not only by the global parameter $\Lambda=2J/\beta^2$ but also by the volatility configuration in the network. We find that local interactions between nodes with different volatility induce a neutralization of group-wise exponents, which lowers the aggregate tail exponent and can drive a condensation transition across $\gamma_{\rm c}=2$. Our results identify volatility mixing as another control mechanism for wealth condensation and highlight the importance of noise heterogeneity in nonequilibrium systems on networks. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13164 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13164v1 Announce Type: new Abstract: Unstable periodic orbits act as organizing structures for classical chaotic systems and underpin quantum scarring. Long known in single-particle systems, genuine quantum scars based on unstable periodic orbits have been recently extended to isolated many-body systems for time-independent Hamiltonians. Their fate under periodic driving, however, remains largely uncharted, challenged by the expectation that these systems should in general heat to infinite temperature. Here, we investigate how genuine scarring competes with the drive in a Floquet many-body system. Using chaotic spin chains, we demonstrate that Floquet states remain scarred in the high-frequency limit. Beyond this static correspondence, we uncover additional, driving-induced Floquet scars with no static analog. We construct a rich dynamical stability diagram with intermediate-frequency regimes of enhanced and quenched scarring, which we understand with a classical analysis of the Lyapunov exponent. Our results position Floquet systems as a natural platform for tuning the scarring behavior of quantum many-body systems. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2603.22849 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.22849v3 Announce Type: replace-cross Abstract: Platinum oxides are vital catalysts, but their limited thermal stability hinders applications. Recent studies have uncovered a structural transition in two-dimensional platinum oxides that significantly enhances their thermal resilience by several hundred Kelvin. Herein, we demonstrate that this enhanced stability stems from the mechanical robustness of the elastic network at the atomic scale. Prior to the transition, an over-constrained lattice generates localized states of self-stress through an incommensurate Moir\'{e} pattern with the platinum substrate, reducing thermal endurance. After the transition, the oxide shifts to a mechanically flexible structure with balanced degrees of freedom and constraints. The isostatic network, together with the platinum substrate, forms a commensurate Moir\'{e} superlattice that relaxes elastic energy and enhances stability. These findings highlight the fundamental role of network connectivity in governing thermal stability, and provide a design principle for catalysts in extreme environments. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2506.18127 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2506.18127v2 Announce Type: replace-cross Abstract: We propose a non-integer-dimensional spatial model for anisotropic solids by incorporating a q-deformed derivative operator, inspired by the Tsallis nonadditive entropy framework. This generalization provides an analytical framework to explore anisotropic thermal properties, within a unified and flexible mathematical formalism. We derive explicit expressions for the phonon density of states and specific heat capacity, highlighting the impact of the deformation parameter q on the thermodynamic behavior. We apply the model to various solid-state materials, achieving excellent agreement with experimental data across a wide temperature range, and demonstrating its effectiveness in capturing anisotropic and subextensive effects in real systems. Beyond providing accurate fits, we anchor the q-deformation in a microscopic disorder/kinetics exponent \mu emerging from conformable dynamics, thereby linking nonextensive statistics to measurable heterogeneity and memory effects. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.09506 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.09506v2 Announce Type: replace Abstract: Active matter systems typically exhibit a trade-off between structural robustness and dynamical freedom, limiting independent control over structure and motion. Here, we show that encoding interactions in a shared field overcomes this constraint, enabling continuous tuning between stable architectures and dynamically active states. Using droplets on a vibrated fluid bath as a minimal realization, we demonstrate that individually unstable units can collectively self-stabilize through field-mediated dynamical bonds. Arising from wavefield interference, these bonds form persistent, self-healing connections that preserve architecture while sustaining motion. Droplet size sets the symmetry of the interactions, with identical droplets forming rigid $\sigma$-like frameworks that enforce triangular packing, while smaller droplets enable $\pi$-like coordination that supports higher-order symmetries. The resulting assemblies exhibit both stability and sustained collective dynamics, including spontaneous rotation and controlled migration. This work establishes a general route to programmable active matter in which shared fields reconcile structural robustness with dynamical freedom. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.03516 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.03516v2 Announce Type: replace Abstract: Deep-subwavelength acoustic resonators are key building blocks of acoustic metamaterials, yet achieving bubble-like resonances in air remains challenging because the Minnaert mechanism relies on the inertia of a surrounding liquid. Here we demonstrate that air-filled soft elastomer shells, termed elasto-bubbles, realize an airborne analogue of the Minnaert resonator. Using impedance-tube measurements together with the theory of layered-bubble scattering, we show that these soft hollow capsules sustain strong monopolar resonances despite being deeply subwavelength. Their resonance frequency, transmission dip, and absorption are quantitatively captured, without adjustable parameters, by a model accounting for shell elasticity and viscoelasticity. Because shell radius and thickness can be tuned independently during fabrication, elasto-bubbles provide a simple and versatile platform for airborne acoustic metamaterials, resonant absorbers, and acoustic filters. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.14056 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14056v1 Announce Type: cross Abstract: We investigate the thermal responses of a harmonic oscillator chain coupled at its boundaries to heat baths held at different temperatures. This setup sustains a steady energy flux, continuously dissipating heat into both reservoirs. By introducing slow variations in the bath temperatures, we quantify the resulting excess heat currents and thereby obtain the nonequilibrium heat capacity matrix at fixed but arbitrary temperature differences. We demonstrate the existence of a well-defined thermodynamic limit for long chains. The specific heat associated with energy exchanges with a single bath depends on the difference in friction coefficients governing the system-bath couplings. That thermokinetic effect is typical for nonequilibrium response. When the couplings with the thermal baths acquire temperature dependence, the specific heat correspondingly inherits a nontrivial temperature dependence, in sharp contrast with equilibrium. Our results provide the first explicit determination of specific heat(s) in a locally interacting, spatially extended driven system. Beyond its exact solvability, the model may offer a natural nonequilibrium extension of the Dulong-Petit law, capturing the high-temperature behavior of driven molecules. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13929 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13929v1 Announce Type: cross Abstract: Porous monolithic photocatalysts based on anatase TiO2 in silica aerogels are promising for air purification. Their bicontinuous spinodal architecture offers high surface area and strong light scattering. However, extracting intrinsic kinetic rates requires accurate optical models. Current methods replace the complex 3D pore network with a homogeneous 1D slab, an approximation whose error is unknown for spinodal geometries. We combine 3D spinodal masks from Cahn-Hilliard simulations with GPU Monte Carlo photon transport to quantify this. We introduce a solid-phase fluence estimator that accounts for catalytic site distribution, comparing it to volume averages and diffusion approximations. The solid phase receives 50% more photons than volume averages at porosity 0.70, rising to 70% at 0.90. This preferential illumination stems from quasi-ballistic paths through pore channels, termed photon channelling. The extracted kinetic descriptor differs by 34% between 3D Monte Carlo and diffusion models. Homogeneous controls show that roughly 50% of the total 73% discrepancy is intrinsic to the bicontinuous structure and cannot be fixed by effective medium theories. These results provide the first quantitative correction for kinetic extraction in such photocatalysts and establish design rules linking synthesis coarsening, pore size, and light efficiency. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13659 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13659v1 Announce Type: cross Abstract: The dynamics of water in electrolyte solutions exhibits a striking, ion-specific anomaly: the diffusion coefficient of water is enhanced relative to the neat liquid in chaotropic CsI solutions, yet suppressed in kosmotropic NaCl solutions. This phenomenon, long challenging for classical force-field-based molecular dynamics, is studied here using classical molecular dynamics simulations with a many-body machine-learned force field (MLFF) trained within the MACE equivariant graph neural network framework. The force field is trained on energies, forces, and stresses computed at the density functional theory level with the revPBE-D3 exchange--correlation functional, which provides a reliable balance between accuracy and computational efficiency for aqueous systems. Simulations of NaCl and CsI aqueous solutions at ambient conditions over a concentration range of 0.89--3.56~mol/kg reproduce the experimentally observed anomalous diffusion and show a quantitative improvement over previous results obtained with the DeePMD framework, trained on the same theory, particularly for NaCl solutions. This improvement is traced to a stronger Na$^{+}$--water interaction in the first hydration shell and the non-negligible retarding contribution of the second hydration shell of Na$^{+}$. For CsI solutions, the water acceleration is shown to be primarily driven by the anion I$^{-}$, whose diffuse and weakly structured hydration shell facilitates rapid water exchange with the bulk. These results are rationalised through a shell-decomposition analysis of time-dependent water diffusivities and ion--oxygen potentials of mean force providing a coherent microscopic picture of the acceleration--retardation mechanism in the studied aqueous electrolytes. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.14109 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14109v1 Announce Type: new Abstract: Granular flows are ubiquitous in nature and industrial applications, yet a complete continuum theory remains a long-standing challenge. The leading empirical approach, {\mu}(I) rheology, lacks microscopic foundations and becomes multivalued in dense, slowly sheared flows where nonlocal corrections are required. Exploiting state-of-the-art high-speed X-ray tomography to investigate microscopic dynamics of dense granular flows in a Couette geometry, we establish a new, universal constitutive law spanning quasi-static to inertial regimes based on structural relaxation, resolving the fundamental difficulty in the original {\mu}(I) framework. By further establishing a non-equilibrium statistical framework for granular flows, we demonstrate an intrinsic analogy between driven granular matter and hard-sphere liquids owing to their identical Carnahan-Starling equation of state, naturally explaining our rheological approach and the emergence of glassy behaviors. Our framework unifies granular rheology with the broader physics of disordered systems and provides a complete, microscopically-based theoretical framework for dense granular flow. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13827 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13827v1 Announce Type: new Abstract: Quantitative modeling has become an essential tool in modern biophysics, driven by advances in both experimental techniques and theoretical frameworks. Powerful high-resolution techniques now provide detailed datasets spanning molecular to tissue scales, allowing to visualize cellular structures with unprecedented detail. In parallel, developments in soft and active matter physics have established a robust theoretical basis for describing biological systems. In this context, two main modeling paradigms have emerged: particle-based models, which explicitly represent discrete components and their interactions, and continuum models, which describe systems through spatially varying fields. We compare these approaches across biological scales, highlighting their respective strengths, limitations, and domains of applicability. To keep our discussion biologically relevant, we focus on five systems of fundamental importance: the cytoskeleton, membranes, chromatin, biomolecular condensates and tissues. With this Review, we thus aim to provide a framework for both theorists and experimentalists to select appropriate modeling strategies, and highlight future directions in biophysical modeling. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13653 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13653v1 Announce Type: new Abstract: A ternary liquid crystalline mixture was designed to obtain a tilted hexatic smectic phase in the glassy state. Structural, electro-optic, and dielectric properties of the mixture are investigated, and selected measurements are also performed for its pure components. In particular, the electron density profile perpendicular to smectic layers is determined from the X-ray diffraction data and compared to the results of density functional theory calculations both for the mixture and pure components. Comparison of the experimental smectic layer spacing and tilt angle in the mixture allows us to assess whether molecular dimerization is likely to occur. On the mesoscopic scale, the helical pitch is determined in the SmC$_A$* phase of the mixture, and selective reflection of light is observed under a polarizing microscope in the SmC*, SmC$_A$*, and SmX$_A$* phases. The glass transition in the smectic X$_A$* phase is observed in calorimetric results. At the same time, the dielectric spectra do not directly reveal the primary $\alpha$-process, although the secondary $\beta$- and $\gamma$-processes are detected. Overall, the results show that the ternary mixture stabilizes a broad SmC$_A$* phase and enables vitrification of the hexatic SmX$_A$* phase, while the structural data suggest a change in the molecular organization between the SmC* and SmC$_A$* phases. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13575 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13575v1 Announce Type: new Abstract: In this perspective article, we discuss bacterial populations as a model system of active matter. It allows for the exploration and characterization of various phases of active matter and brings rich implications for both physics and biology. Specifically, we focus on active gas, active liquid, active glass and active liquid crystal states observed in bacterial populations and describe how these differ from their thermal counterparts. A few future directions are also discussed that will deepen the physical interest in active matter as a new type of material, with its implications for several life phenomena observed in bacterial populations and other biological systems. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13499 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13499v1 Announce Type: new Abstract: The sodium dodecyl sulfate (SDS) surfactant is widely used in various applications, such as household products (e.g., shampoos, toothpaste, detergents, and cleaning products) and food manufacturing (e.g., emulsifiers). To investigate its properties via computer simulation, various models have been developed, including coarse-grained (CG) models that are suitable for capturing a surfactant's self-assembly and fundamental properties for aqueous systems with a surfactant, such as surface tension. Here, we present a CG model for SDS/water systems for many-body dissipative particle dynamics (MDPD), which is based on the MDPD--Martini force field (FF). In the model, charged groups, namely, the SDS sulfate headgroup and the sodium cation, are explicitly modeled following the standard mapping of the Martini force field for molecular dynamics (MD), while the remaining interactions have been obtained from previous MDPD--Martini models for lipid systems, thus demonstrating their transferability. Various relevant system properties, such as the coherent scattered intensity and surfactant distribution at the liquid--vapor surface, are investigated, and results are compared to those obtained by MD simulations and experiments at different surfactant concentrations. Our findings indicate that MDPD--Martini models can offer a credible alternative to MD--Martini models for systems with explicit charges as shown here for SDS. Moreover, MDPD--Martini models reproduce nicely the experimental surface tension isotherm, in contrast to MD simulations. In view of the transferability of the MDPD--Martini interactions, the model parameters of this study can be tested and used to simulate a wider range of soft-matter systems. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13420 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13420v1 Announce Type: new Abstract: Freezing of complex fluids is central to a wide range of natural and technological processes, where the interplay between heat transport, solute redistribution, and interfacial deformation gives rise to complex morphologies. Unlike simple liquids, polymer solutions exhibit strongly coupled transport and rheological properties that evolve dynamically during solidification, making their freezing behavior difficult to predict. Here, we examine the freezing of polymer solution droplets spanning dilute to entangled regimes. We find that droplet morphology and freezing dynamics in viscous solutions are governed by a single dimensionless parameter, the Capillary--Lewis number, which captures the competition between viscous stresses, capillarity, and solute transport. Circularity, radial deformation, and freezing time collapse onto a master curve spanning nine orders of magnitude, revealing a transition near unity corresponding to the point at which solute diffusion can no longer relax concentration gradients ahead of the freezing interface. This collapse holds across distinct polymer chemistries within the viscous fluid regime, while deviations emerge when the material exhibits elastic-dominated response ($G' > G''$), indicating the breakdown of purely transport--capillary control. These results establish a minimal transport--mechanics framework linking solute redistribution to interfacial deformation during freezing polymer solutions. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.13391 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13391v1 Announce Type: new Abstract: We study synchronization of two cardiomyocytes mediated by elastic interactions through the substrate. Modeling each cell as an oscillating force dipole governed by a Rayleigh-type equation, we derive an effective mechanical coupling from the elastic response of the surrounding medium. Using phase reduction theory, supported by direct numerical simulations, we obtain a dynamical phase description for two cardiomyocytes that predicts geometry-dependent selection of synchronized states. Depending on the mutual orientation, the cells robustly converge to either in-phase or anti-phase beating, yielding an orientation-dependent state map with a nontrivial state boundary. The synchronization time also depends strongly on the distance and mutual orientation of the cells. These results bridge earlier energetic two-body theory and dynamical single-cell theory, and provide a dynamical framework for elastic synchronization of cardiomyocytes. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2603.28849 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.28849v2 Announce Type: replace-cross Abstract: In one dimension, strongly correlated gapless systems are highly constrained due to conformal invariance, leading to the decoupling of low energy degrees of freedom corresponding to different symmetry sectors. The most familiar example of this is spin-charge separation. Here, we extend this mechanism to the non-Hermitian realm by demonstrating that skin effects corresponding to different symmetry sectors exhibit an emergent decoupling. We establish this for $N$ flavor fermions and demonstrate it numerically for the special case of the Hubbard model, in which spin and charge skin effects separate at low energies. Finally, we construct an interaction-enabled $E_8$ skin effect with no free fermion counterpart. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2512.07473 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2512.07473v3 Announce Type: replace-cross Abstract: We investigate the critical temperature of a relativistic Bose-Einstein condensate of charged bosons driven by rotation in a parallel magnetic field [Y. Liu and I. Zahed, Phys. Rev. Lett. 120, 032001 (2018)]. For non-interacting bosons, the critical temperature can only be determined for a system with fixed angular momentum. We find that the critical temperature of the non-interacting system vanishes due to the fact that the system is quasi-one-dimensional, indicating that non-interacting bosons cannot undergo Bose-Einstein condensation. For interacting bosons, we investigate a system with quartic self-interaction. We show that the order parameter vanishes and the off-diagonal long-range order is absent at any nonzero temperature because of the quasi-one-dimensional feature, in accordance with the Coleman-Mermin-Wagner-Hohenberg theorem. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2603.25784 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.25784v2 Announce Type: replace Abstract: Continuous control over lattice geometry, when combined with long-range interactions, offers a powerful yet underexplored tool to generate highly frustrated quantum spin systems. By considering long-range dipolar antiferromagnetic interactions on a breathed Kagome lattice, we demonstrate how these tools can be leveraged to stabilize a chiral spin liquid. We support this prediction with large-scale density-matrix renormalization group calculations and explore the surrounding phase diagram, identifying a route to adiabatic preparation via a locally varying magnetic field. At the same time, we identify the relevant low-energy degrees of freedom in each unit cell, providing a complementary language to study the chiral spin liquid. Finally, we carefully analyze its stability and signatures in finite-sized clusters, proposing direct, experimentally viable measurements of the chiral edge mode in both Rydberg atom and ultracold polar molecule arrays. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2603.25045 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.25045v2 Announce Type: replace Abstract: We investigate the dynamics of two identical spinless fermions on a one-dimensional lattice with open boundary conditions (OBC), subject to quasiperiodic long-range interactions. Using numerical exact diagonalization (ED), we study this non-integrable system as a continuous-time quantum walk and uncover a robust correlated dynamical regime. This regime, characterized by an approximately constant inter-particle distance, emerges under sufficiently strong quasiperiodic modulation of the long-range interactions. Further, the study shows that the behavior is determined by the nature of the interaction and the choice of boundary condition. Notably, by tuning the phase of the quasiperiodic modulation, we observe three distinct manifestations of this phenomenon: localization, nearest-neighbor separation oscillations, and next-nearest-neighbor separation transitions -- each arising for specific initial separations. Furthermore, we identify the suppression of entanglement entropy in the system, including instances of oscillatory behavior. Our results highlight how quasiperiodic long-range interactions shape few-body quantum dynamics. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2511.01138 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2511.01138v3 Announce Type: replace Abstract: Advances in experimental control of interacting quantum many-body systems with multiple tunable parameters-such as ultracold atomic gases and trapped ions-are driving rapid progress in quantum thermodynamics and enabling the design of quantum thermal machines. In this work, we utilize a sudden quench approximation as a means to investigate the operation of a quantum thermodynamic Otto cycle in which multiple parameters are simultaneously controllable. The method applies universally to many-body systems where such control is available, and therefore provides general principles for investigating their operation as a working medium in quantum thermal machines. We investigate application of this multi-parameter quench protocol in an experimentally realistic one-dimensional Bose gas, as well as in the transverse-field Ising model. We find that such a multi-parameter Otto cycle, when operating as an engine, outperforms not only its constituent single-parameter Otto cycles in terms of the net work and efficiency, but also the combined net work of its constituent engine cycles when added together independently. We also find that a similar multi-parameter enhancement applies to the coefficient of performance when the Otto cycle operates as a refrigerator. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13160 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13160v1 Announce Type: cross Abstract: We introduce a framework for realizing universal fermionic quantum processing with globally controlled itinerant fermionic particles. Our approach is tailored to the example of neutral atoms in optical lattices, but transposes to other setups with similar capabilities. We give constructive protocols to realize arbitrary fermionic processes, with time-dependent control over global parameters of the experimental setup, such as tunneling and interaction in a Fermi-Hubbard type model. We first prove the universality of our framework and then discuss implementation variants, such as hybrid analog-digital simulation of extended Fermi-Hubbard models, e.g., with long-range couplings. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.14039 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14039v1 Announce Type: new Abstract: The interplay between charge and spin dynamics is at the heart of strongly correlated materials. Inspired by recent quantum simulation experiments, we develop a conserving diagrammatic method to describe the Fermi-Hubbard model for strong repulsion and small hole doping away from the half-filled anti-ferromagnetic ground state. We show that doping leads to four hole pockets in the Brillouin zone formed by magnetic polarons, which become increasingly damped with hole concentration. Likewise, the magnon spectrum of the anti-ferromagnet softens and dampens with doping due to hole-induced magnetic frustration. This gives rise to a suppression of the anti-ferromagnetic correlations in agreement with recent experiments. We then calculate the response of the system to a lattice modulation and recover the qualitative difference between in-phase and out-of-phase modulations seen in experiments, which was interpreted as signs of pseudogap physics. Our results indicate that the complex competition between spin and charge degrees of freedom and the emergence of the pseudogap phase may be usefully analyzed for small dopings, where systematic theories can be developed. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13370 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13370v1 Announce Type: new Abstract: Experiments on attractive Bose-Einstein condensates (BECs) have unlocked many intriguing out-of-equilibrium dynamics through the interplay between matter-wave dispersion and nonlinear attractive interaction. Competition between these effects leads to fascinating phenomena such as wave collapse, modulational instability, and formation of multidimensional bright solitons. This chapter reviews experimental studies on attractive condensates, with a primary focus on alkali atoms featuring two-body contact interactions. We review recent experimental advances in optical trapping and interaction control techniques, which have enabled new studies on attractive condensates in three and also in lower dimensions. Specifically, we discuss pioneering and recent experimental observations on the dynamics and stability of attractive BECs, including the formation of bright solitons, their collisions, and excitations in quasi-one-dimensional traps. Recent observations of the elusive two-dimensional Townes solitons and vortex solitons are also discussed in this Chapter. We then highlight an experimental technique revealing the nonclassical signatures of modulational instability in an attractive condensate. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13257 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13257v1 Announce Type: new Abstract: Arrays of Rydberg atoms provide a powerful platform for exploring constrained quantum dynamics and nonergodic many-body phenomena. While most work has focused on single-species systems, multispecies architectures offer additional interaction channels and enable new forms of dynamical constraints. We study the nonequilibrium dynamics of one-dimensional dual-species Rydberg chains of Cs and Rb atoms with species-dependent van der Waals interactions. Using large-scale matrix product state simulations, we show that the competition between intra-species repulsion and inter-species attraction induces dynamical fragmentation, marked by the coexistence of extended frozen regions and localized oscillatory sectors. The frozen regions act as emergent barriers that isolate and protect coherent dynamics. In the purely repulsive regime, we find that species-selective quenches drive spontaneous fragmentation, leading to dynamically disconnected regions with irregular revivals. These phenomena are robust across interaction regimes, revealing a universal mechanism for fragmentation and establishing multispecies Rydberg arrays as a versatile platform for exploring nonequilibrium quantum dynamics beyond single-species systems. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13892 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13892v1 Announce Type: cross Abstract: Time-resolved scanning near-field optical microscopy (tr-SNOM) enables the measurement of the dynamic optical response of functional surfaces beyond the diffraction limit. Experimental challenges are imposed both by the use of a pulsed light source, and by the need for interferometric signal modulation to isolate the near-field contribution. We present a novel experimental approach to retrieve the tr-SNOM signal using a 200 kHz laser system and pseudo-heterodyne modulation. We circumvent the Nyquist limit for spectral demodulation by sampling modulation phases, pump intensity and SNOM signal for every laser shot. A general time-resolved SNOM signal is derived, independent of detection scheme or physical assumptions about the near-field enhancement, and is successfully measured and isolated on WS$_2$ monolayer and multilayer regions. We confirm localization by signal-distance curves, spatial confinement at material boundaries, and by identifying signal contributions at individual modulation harmonics. Disentangling the dynamic contributions enables us to extract the dynamic dielectric function of the sample. Showing the capability of phase-domain sampling paves the way to integration of more diverse and specialized light sources, growing the potential of optical ultrafast near-field measurements. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13382 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13382v1 Announce Type: cross Abstract: We investigate a many-body interacting system of quantum kicked rotors, where each rotor resides in its respective quantum resonance. Rich many-body dynamics are found to emerge from the interplay between the principal and secondary resonances. In particular, for both the wavepacket and bipartite entanglement entropy, we analytically demonstrate three distinct dynamical regimes -- quadratic spreading (growth), period-2 oscillation, and their hybrid -- governed by the respective symmetries of the relevant potentials. Based on these symmetries, the connection between the wavepacket and the entanglement dynamics is illustrated. Other related issues are also discussed, including higher-order resonance effects, the robustness of the predicted dynamical behaviors, extension to many-body kicked tops, and relevance to experimental studies. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13379 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13379v1 Announce Type: cross Abstract: Chern insulator systems are realizable in numerous physical systems and can support robust nonreciprocal transmission of energy. A routing functionality constructed from two counter-oriented Chern insulator regions, using coupled Haldane type systems is proposed. By adjusting the strength of a magnetic field and the frequency of an antenna source, it possible to steer the flow of energy: completely to the left, completely to the right, or split. Alternatively, two sources can be used to direct the flow of energy. This formulation has the potential to serve as a robust and reconfigurable component in optical transmission. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13110 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13110v1 Announce Type: cross Abstract: In a recent work, Somogyfoki et al. (J. Non-Equilib. Thermodyn. 50, 59-76, 2025) analysed the linear stability of homogeneous equilibrium in third-order non-Fourier heat conduction within the framework of non-equilibrium thermodynamics with internal variables. They identified a stability condition, their equation (49), which could not be derived from the standard thermodynamic inequalities for the 2X2 conductivity blocks, and concluded that the Second Law does not guarantee stability in the most general case. Here we show that this conclusion was due to an overly conservative proof strategy: the standard thermodynamic conditions (concave entropy and non-negative entropy production, as expressed by the $2\times2$ block positive-definiteness inequalities (19)-(20) of the original paper) do suffice for linear stability. The key observation is that all coefficients of the dispersion polynomial remain positive for all physical wave numbers because their structure prevents positive real roots. This result confirms that thermodynamics, understood as a stability theory, ensures fundamental dynamic stability in all thermodynamically consistent third-order extended heat conduction theories. A comparison with the rate-equation approach of Giorgi, Morro and Zullo (Meccanica 59, 1757-1776, 2024) is also presented. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13808 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13808v1 Announce Type: cross Abstract: When charged particles are subjected to strong magnetic fields, they form discrete energy levels known as Landau levels. The Landau levels consist of a series of degenerate states of Landau modes, making them a promising platform for large-capacity information processing. However, to date, exploiting the high-order Landau modes and control their spatial distributions has remained elusive. Here, we propose to construct magnetic fields, electric fields, and imaginary momentum simultaneously to reshape high-order Landau modes in non-Hermitian systems. By building a non-Hermitian electric circuit platform, we experimentally realize pseudomagnetic fields via inhomogeneous coupling and pseudoelectric fields via a gradient on-site potential, while simultaneously introducing an imaginary momentum via non-reciprocal coupling. We directly observe multi-frequency single-peak localization of high-order Landau modes. Our work provides a universal method for manipulating high-order Landau modes and exploring applications in nonHermitian systems, such as frequency multiplexing and wave packet reshaping. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13775 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13775v1 Announce Type: cross Abstract: Nanoplasmonic modification of scintillation has so far been explored mainly in the weak-coupling regime, where changes in the local density of optical states enhance radiative recombination via Purcell-type rate engineering. By contrast, strong light-matter coupling generates hybrid states that modify emission dynamics beyond simple decay-rate acceleration, but its implications for scintillator nanocrystals (NCs) under ionizing radiation remain poorly understood. All of these effects are beneficial for near-infrared scintillators, which are typically slow and have low brightness. Here, we present a quantum-optical framework to investigate how near-infrared scintillator NCs coupled to nanoplasmonic antennas evolve from weak coupling toward strong light-matter coupling. We compare broad- and narrow-antenna platforms with single and periodic Au nanorods and benchmark them against conductive plasmonic antennas based on indium tin oxide and graphene. As representative emitters, we consider wide-band PbS NCs and narrow-band cubic Lu2O3:Er3+ scintillators. The calculations show that the onset of strong-coupling signatures is jointly governed by emitter dephasing and the antenna linewidth, with narrow-band emitters coupled to spectrally narrow antennas providing the most favorable conditions. Among the platforms considered, graphene gives the lowest threshold (g = 4 meV) for observable coherent exchange owing to its ultranarrow antenna linewidth (\k{appa} = 3.5 meV). These results identify near-infrared conductive nanoantennas, particularly graphene-based ones, as promising platforms for accessing hybrid scintillation regimes relevant to radiation detection. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13744 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13744v1 Announce Type: cross Abstract: Multilayered thin-film structures are frequently encountered in industrial applications, where accurate thermal property characterization is essential for performance optimization. These films, typically ranging from nanometers to micrometers in thickness, often exhibit anisotropic thermal conductivity and non-bulk heat capacity, which are challenging to measure. In this study, we introduce a variable-spot-size and multi-frequency square-pulsed source (SPS) method for the simultaneous determination of anisotropic thermal conductivities, heat capacities, and interfacial thermal conductance in multilayered systems. By leveraging a broad modulation frequency range (1 Hz to 10 MHz) and tunable laser spot sizes, the SPS method enhances sensitivity to different thermal parameters across layers. We validate this approach on a silicon-on-insulator (SOI) sample comprising a 1.59 um Si layer, 1.03 um SiO2 layer, and a silicon substrate with a 122 nm aluminum (Al) transducer. The SPS method successfully extracts seven key thermal parameters, including the in-plane and cross-plane thermal conductivities and heat capacity of the Si film, the thermal conductivity and heat capacity of the SiO2 layer, the thermal conductivity of the substrate, and the interfacial thermal conductance between Al and Si. Temperature-dependent measurements from 80 to 500 K showed excellent agreement with literature values and first-principles predictions, confirming the method's accuracy and reliability. These results demonstrate the SPS method as a powerful tool for comprehensive thermal characterization of complex multilayered structures, with implications for both fundamental research and practical applications. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13741 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13741v1 Announce Type: cross Abstract: Solid-liquid interfacial thermal conductance (ITC) critically influences heat transport in microfluidic, electronic, and energy systems, yet most optical thermometry techniques are limited to specific metal-liquid interfaces. In this work, we introduce a universal broadband square-pulsed thermometry method that enables simultaneous quantification of ITC across a wide range of arbitrary solid-liquid interfaces, while also providing accurate measurements of nanoscale liquid-film thickness. To validate the method, we applied it to Al-water interfaces, yielding ITC values in the range of 50-55 MW m^(-2) K^(-1), consistent with prior studies. The technique also reveals markedly lower ITCs for glass-water (9.9 MW m^(-2) K^(-1)) and Si-water (5.7 MW m^(-2) K^(-1)), and further measurements on Al-silicone oil (~10 MW m^(-2) K^(-1)) and PMMA-silicone oil (~0.4 MW m^(-2) K^(-1)) extend the validation to highly viscous nonpolar liquids and polymer-liquid interfaces. These results highlight the capability of the method to capture thermal transport differences across diverse solid-liquid combinations. Further comparisons with acoustic/diffuse mismatch models and molecular dynamics simulations, together with theoretical analysis, highlight the influence of vibrational mismatch, wettability, and surface condition on interfacial thermal transport. This broadly applicable technique enables rapid, quantitative characterization of solid-liquid interfacial thermal transport, with broad implications for interfacial heat transfer science and technology. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13647 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13647v1 Announce Type: cross Abstract: To describe the interactions in magnetically soft particle systems either numerical full-field methods or dipole models are used. Whereas the former are computationally challenging, simple dipole interactions are largely underestimating the actual forces when particles get closer. Based on the full 2-body solution, an analytic approximation scheme for many-body full-field interactions is developed. The concept is formulated in terms of an improved operator that is equivalent to the classical dipole form. The full interaction operator allows to describe cluster formation and dispersion among particles in applied magnetic fields very compactly and highly efficient. In view of its simple 'dipole-like' form, the implementation is straightforward in many areas where magnetically soft objects are used. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13497 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13497v1 Announce Type: cross Abstract: Magnetic skyrmions and higher-order topological spin textures offer rich opportunities for multi-level information encoding, yet their deterministic stabilization and transformation under geometric confinement at room temperature remain poorly understood. Here, we demonstrate that geometric confinement acts as a robust and universal control parameter that governs a hierarchical transformation pathway of chiral spin textures in Pt/Co/W multilayer micro-tracks. As the confinement increases, extended labyrinth domains fragment into isolated skyrmions, followed by the systematic suppression of skyrmion pairs and the preferential stabilization of compact higher-order textures. We find that confinement strongly enhances the formation of skyrmioniums via recombination and promotes their subsequent evolution into uniform skyrmion bags by capturing additional skyrmions. Statistical analysis reveals a confinement-driven redistribution of topological populations, with skyrmion bags emerging as the dominant state in the narrowest tracks. Supported by micromagnetic simulations, our results establish geometric confinement as a deterministic selector of complex topological textures and reveal a previously unexplored route for engineering higher-order skyrmionic states at room temperature. These findings provide a scalable materials strategy for multistate skyrmion-based spintronic and memory architectures. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13429 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13429v1 Announce Type: cross Abstract: Coherent control of quantum materials has progressed along two major fronts: nonlinear phononics, which reshapes lattices to induce emergent states, and Floquet engineering, which tailors electronic band reconstruction via time-periodic driving. Both mechanisms face fundamental limitations at terahertz (THz) frequencies: phononic nonlinearities are intrinsically weak in standard lattices, while electronic Floquet states are often constrained by rapid decoherence upon light-off and by a scarcity of coherence-resolved, multi-correlation probes beyond (quasi-)stationary band structures. Here we report an extreme THz nonlinear-phononics mechanism in $\text{Ta}_\text{2}\text{NiSe}_\text{5}$, where a highly susceptible non-equilibrium electronic correlation bath dramatically amplifies lattice nonlinearities under coherent driving. Utilizing THz two-dimensional spectroscopy as a coherence-tomography tool, we resolve an exceptionally rich landscape of approximately 30 distinct multi-order quantum pathways, including high-harmonic phonon generation, multi-quantum coherences, and multi-wave anharmonic cross-mode mixing. The density and complexity of this extreme manifold establishes a new benchmark for THz nonlinear phononics, as the multi-order quantum pathways surpass the limits of conventional lattice responses. These high-order signals collapse above ~100~K, defining an electronic correlation scale of a coherence-imprinted hybrid electronic-phonon order that governs the sustainability of high-order quantum correlations and nonlinear pathways beyond linear and equilibrium responses. Our results establish a route for correlation-boosted, phonon-anchored periodic Hamiltonian engineering and for certifying such periodically-driven states via multi-correlation coherence tomography. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13222 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13222v1 Announce Type: cross Abstract: We propose a model that extends the standard depinning paradigm by incorporating an aging mechanism into the local pinning force. This favors oscillations between a stuck state of large pinning, and a slipping state of smaller pinning. We show that for mean field interactions between sites this mechanism can lead to the appearance of ``king avalanches" and global instabilities, producing a global oscillatory stick-slip stress regime. We construct the phase diagram for this mean field case and identify regions of smooth dynamics, pure stick-slip, and bistability. Crucially, when considering two-dimensional systems with short-range interactions we find that states of global stress oscillation persist, but in contrast to the mean field case, no system-size avalanches appear. Instead, we observe alternating temporal intervals of larger and lower avalanche activity that correlate with the stress oscillations. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13139 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13139v1 Announce Type: cross Abstract: Machine learning (ML) is transforming modern physics research, but practical, hands-on experience with ML techniques remains limited due to cost and complexity barriers. To address this gap, we introduce an affordable, autonomous, Internet-of-Things (IoT)-enabled experimental platform designed specifically for applied physics education. Utilizing an Arduino microcontroller, a customizable multi-wavelength light emitting diode (LED) array, and photosensors, our setup generates diverse, real-time optical datasets ideal for training and evaluating foundational ML algorithms, including traversal methods, Bayesian inference, and deep learning. The platform facilitates a closed-loop, self-driving experimental workflow, encompassing automated data collection, preprocessing, model training, and validation. Through systematic performance comparisons, we demonstrate the superior ability of deep learning to capture complex nonlinear relationships compared to traversal and Bayesian methods. At approximately $60, this open-source IoT platform provides an accessible, practical pathway for students to master advanced ML concepts, promoting deeper conceptual insights and essential technical skills required for the next generation of physicists and engineers. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14082 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14082v1 Announce Type: new Abstract: Materials discovery is fundamental to advance next-generation technologies as well as for sustainable and circular economy. Beyond computational screening, generative models are efficient at finding materials with desired properties, via multi-modal learning using multiscale data. This perspective examines the landscape of generative design for inorganic materials and discusses the integration of multi-modal learning with high-throughput experimental validation. We contextualize these challenges through the lens of a generative design framework as a unified approach to address the data-driven inverse design of functional materials. The central idea of the framework is constructed around a foundation AI model for inorganic materials interlinked deeply with various property databases and high-throughput experiments via a machine learning driven closed loop, which enables the framework to solve key challenges in functional materials. We argue that domain-specific implementations of such integrated workflows represent a promising pathway toward the unresolved challenge of data-driven inverse design for atom-engineered inorganic functional materials. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.14078 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14078v1 Announce Type: new Abstract: Long-term chemical durability of glass, crucial for immobilizing nuclear waste, is governed by glass properties such as composition, surface geometry, as well as external factors like thermodynamic conditions and surrounding medium. Despite decades of research, there are no models that account for these intrinsic and extrinsic factors to predict the dissolution rates of glass compositions. To address this challenge, we evaluate the role of natural language embeddings capturing the synthesis and testing conditions in enhancing the predictability of glass dissolution. Evaluating the approach on hand-curated ~700 datapoints extracted from the literature, we reveal that the machine learning (ML) model including natural language embeddings (NLP-ML) outperforms classical ML model in predicting glass dissolution rate. Furthermore, we developed a generalizable ML model by transforming the compositional features to structural descriptors of glass alongside NLP-derived features, enabling extrapolation capability to glass compositions with completely new elements absent in the training data. Evaluating this model on a completely new dataset of glass compositions 34 chemical components in contrast to the training dataset that had only 28 components, we demonstrate that the model indeed exhibits generalizability to glass compositions that are out-of-distribution. Altogether, this integrated approach offers a pathway towards high-fidelity glass dissolution prediction and accelerate the discovery of novel glass compositions with tailored durability for sustainable nuclear waste management. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13960 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13960v1 Announce Type: new Abstract: Twist-engineering of topological phases in two-dimensional materials offers a powerful route to modulate electronic structure beyond conventional strain or chemical control. In particular, group 15 (pnictogens) monolayers such as bismuthene provide an ideal platform due to their strong intrinsic spin-orbit coupling (SOC) and robust topological character. Here, we investigate a previously unexplored heterostructure consisting of a $\beta$-bismuthene monolayer rotated by 30$^\circ$ on a planar bismuthene layer stabilized on a SiC(0001) substrate. Using first-principles calculations, we demonstrate that this specific rotational alignment induces a unique interlayer orbital hybridization which, combined with the strong SOC and the naturally broken inversion symmetry, gives rise to a pronounced Rashba spin-splitting, absent in the isolated monolayers. The topological nature of the system is confirmed through the calculation of the Z2 topological invariant and Spin Hall Conductivity (SHC), revealing a robust Quantum Spin Hall (QSH) phase with an enhanced topological response compared to the individual layers. Furthermore, we explore the chemical tunability of this system via Sb substitution, showing that the gradual reduction of SOC systematically narrows the band gap while preserving the non-trivial topology. Our results establish large-angle twisted group 15 heterostructures as a versatile platform for engineering spin-orbit-driven phenomena and advancing topological spintronics. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13948 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13948v1 Announce Type: new Abstract: The coexistence of topological states with different dimensionalities in a single crystalline system offers a unique platform to study the interplay of distinct fermionic excitations. Here, integrating first-principles calculations with symmetry analysis, we propose the three-dimensional boron allotrope $P6_3$-$\text{B}_{30}$ as an ideal, structurally stable candidate for exploring multidimensional topological physics. Benefiting from the practically negligible spin-orbit coupling of the light-element framework, $P6_3$-$\text{B}_{30}$ operates as a pristine spinless topological semimetal. We show that the combined time-reversal and twofold screw symmetry ($\mathcal{T}S_{2z}$) enforces a robust two-dimensional nodal surface on the $k_z = \pi$ plane via a Kramers-like degeneracy. Concurrently, the system hosts a diverse set of zero-dimensional Weyl fermions -- including an unconventional double-Weyl point ($\mathcal{C} = -2$), conventional Type-I WPs ($\mathcal{C} = -1$), and completely tilted Type-II WPs ($\mathcal{C} = +1$) -- emerging at the high-symmetry points $\Gamma$ and K, as well as along the H-K path, protected by $C_6$ and $C_3$ crystalline rotational symmetries. Crucially, the substantial momentum-space separation between the nodal surface and Weyl points allows for their unambiguous independent resolution. Calculations of the (100) surface states reveal distinct, nontrivial Fermi arcs connecting Weyl nodes of opposite chirality. This work establishes $P6_3$-$\text{B}_{30}$ as a compelling material platform for investigating the physics of multidimensional hybrid topological fermions and their interplay. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13931 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13931v1 Announce Type: new Abstract: Topologically nontrivial magnetic textures such as skyrmions offer promising opportunities for spintronic applications. In recent years, it has been shown that the magnetic properties of layered materials can be affected by depositing chiral molecules on the surface, while the influence of chiral overlayers on skyrmion properties such as their stability and interactions remains largely unexplored. To address this challenge, we employ wide-field nitrogen-vacancy (NV) magnetometry to directly image skyrmions in chiral-molecule-functionalized magnetic thin films, enabling quantitative mapping of magnetic stray fields over extended areas under ambient conditions. Using pixel-resolved optically detected magnetic resonance (ODMR) combined with controlled magnetic fields, we reproducibly nucleate and probe skyrmion states in CoFeB ferromagnetic samples, enabling quantitative investigation of their properties. We find evidence for enantioselective and magnetic-field-polarity-dependent modifications of skyrmion diameter, spacing, and shape, pointing to a possibility of molecular control of topological spin textures via magneto-chiral coupling. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13821 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13821v1 Announce Type: new Abstract: The coexistence of step bunching and step meandering remains contradictory in the understanding of the unstable step-flow growth. Considered separately, the two instabilities have generated rich but largely independent modeling traditions. Especially, the one-dimensional framework faces a fundamental difficulty once bunching and meandering occur simultaneously -- step bunching is usually associated with an inverted Ehrlich--Schwoebel effect, whereas step meandering is associated with a direct one. The key experiments also focus mainly on the two basic limiting cases. How, then, can both instabilities coexist within the same growth process once the simultaneous occurrence of bunching and meandering cannot be adequately captured as a simple superposition of the two? In this work, we confront results from two substantially different approaches: a (2+1)D Vicinal Cellular Automaton based model (VicCA) and a differential-difference PDE-based description combining a model of step bunching with a relaxation term in the perpendicular direction. The continuous framework enables to explore long-time scales evolution to find large variety of surface patterns. Introducing a proper shape of the potential energy landscape in the VicCA model produces similar patterns and links both models on the level of parameters. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13768 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13768v1 Announce Type: new Abstract: Chalcogenide perovskites have emerged as promising lead free materials for photovoltaic and thermoelectric applications. Among them, BaZrS3 has attracted particular attention due to its thermal and chemical stability, favorable optoelectronic properties, and low thermal conductivity. Here, we combine molecular dynamics and Monte Carlo simulations based on machine learned interatomic potentials with scanning transmission electron microscopy to investigate mixing thermodynamics and phase stability in the BaZr(S,Se)3 system. We identify an unusual ordered structure that persists at room temperature, most prominently at 33% S, where S and Se atoms form alternating layers within the crystal. Free energy calculations yield the temperature composition phase diagram, including a nonperovskite delta phase in the Se rich limit and a perovskite phase in the S rich limit, separated by a broad two phase region. Analysis of the dielectric function and the absorption coefficient demonstrates that composition, crystal structure, and anion ordering jointly control the optical band gap. Selenium alloying enables tuning between approximately 1.6 and 1.9eV, while anion ordering within a given composition reduces the gap by about 0.12eV. Lastly, variations between structural polymorphs give rise to band gap differences of up to 0.4eV. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13752 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13752v1 Announce Type: new Abstract: The physical properties of matter are typically described by coefficient matrices governed by crystal symmetry. Applying spatial operations, such as rotation, inversion, and mirror, to these matrices provides an effective approach for investigating material properties. However, the diversity of coefficient matrix types complicates their transformation via simple matrix multiplication, and existing methods suffer from cumbersome notation, high computational cost, and lack of intuitive interpretation. Moreover, as coefficient matrices grow in size, conventional approaches become increasingly inadequate. We present a generalized ``input-coefficient-output (ICO)" approach for constructing spatial operation matrices applicable to coefficient matrices across diverse physical systems, including but not limited to high-order nonlinear optics, elastic mechanics, electricity and magnetism. Our approach offers a concise formalism that enables intuitive reasoning about spatial transformations while delegating intensive computations to computational tools, which is analogous to the role of Feynman diagrams in facilitating understanding in physics. This method also offers valuable insights for future theoretical and experimental research. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13640 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13640v1 Announce Type: new Abstract: Van der Waals (vdW) heterostructures enable tailored electronic and magnetic phases by stacking atomically thin layers with pristine interfaces. Here, we investigate fully 2D Cr2Ge2Te6/WTe2 heterostructures and identify a strong enhancement of ferromagnetism in Cr2Ge2Te6 (CGT). Magnetotransport measurements across multiple devices with WTe2 thicknesses ranging from monolayer to bulk reveal a robust anomalous Hall effect together with a more than twofold increase of the Curie temperature and substantially enhanced coercive fields. Interface microscopy confirms chemically abrupt vdW interfaces with no detectable interdiffusion, while control experiments rule out processing- or stray-field-induced artifacts. Our experiments and theoretical calculations demonstrate that interfacial charge transfer renders CGT conductive and that proximity-induced lattice distortions in CGT enhance exchange and magnetocrystalline anisotropy. These results establish strain-mediated lattice reconstruction as a strategy for engineering high-temperature magnetic order in 2D heterostructures and clarify that modifications within the magnetic layer itself can govern proximity effects in vdW stacks. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13442 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13442v1 Announce Type: new Abstract: Lead-halide perovskites are a promising material platform as semiconductors in next-generation solar cells because of their solution processability, defect tolerance, and tunable optoelectronic properties. While iodide-bromide perovskite compositions have shown promise as wide bandgap absorbers, they also suffer from significant instabilities under operating conditions. Triple-halide perovskites, where chloride is additionally incorporated, have demonstrated improved stability and performance over their double-halide counterparts; however, relatively little is understood about halide miscibility and incorporation in these novel materials. While bulk metrics such as lattice spacing and optical bandgap can be consistent with incorporation of chloride into a single phase, these results are not sufficient to fully describe the material as having homogeneous mixing on the X site. This uncertainty motivates the use of a more local probe to study short-range halide coordination and illuminate the role of chloride in triple-halide perovskites. We use cryogenic X-ray absorption spectroscopy (XAS) to characterize lead-halide bonds in a range of single-, double-, and triple-halide perovskite compositions. We show formation of a single-phase triple-halide perovskite whose miscibility is mediated by bromide content. We identify signatures of halide mixing from the Pb L3-edge EXAFS of mixed double- and triple-halide perovskites using both quantitative fits and Cauchy wavelet transforms. Finally, using wavelet transforms of the Br K-edge EXAFS, we demonstrate via forward scattering amplified 3rd shell halide-halide interactions that all three halides coordinate at short range in a fully mixed perovskite phase. These results are a step forward in the understanding of local structure that is required to fully describe and optimize halide incorporation for novel perovskite compositions. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13354 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13354v1 Announce Type: new Abstract: The discovery of inorganic crystal structures with targeted properties is a significant challenge in materials science. Generative models, especially state-of-the-art diffusion models, offer the promise of modeling complex data distributions and proposing novel, realistic samples. However, current generative AI models still struggle to produce diverse, original, and reliable structures of experimentally achievable materials suitable for high-stakes applications. In this work, we propose a generative machine learning framework based on diffusion models with adaptive constraint guidance, which enables the incorporation of user-defined physical and chemical constraints during the generation process. This approach is designed to be practical and interpretable for human experts, allowing transparent decision-making and expert-driven exploration. To ensure the robustness and validity of the generated candidates, we introduce a multi-step validation pipeline that combines graph neural network estimators trained to achieve DFT-level accuracy and convex hull analysis for assessing thermodynamic stability. Our approach has been tested and validated on several classical examples of inorganic families of compounds, as case studies. As a consequence, these preliminary results demonstrate our framework's ability to generate thermodynamically plausible crystal structures that satisfy targeted geometric constraints across diverse inorganic chemical systems. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.13657 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13657v1 Announce Type: cross Abstract: Ultrasound-guided drug and gene delivery (USDG) is a promising non-invasive approach for targeted therapeutic applications. Mechanical properties of encapsulated microbubbles (EMBs), which serve as contrast agents, strongly affect their specific interactions with ultrasound and are thus critical to the success and efficiency of USDG. Accurate calibration of high-fidelity particle-based models of EMB capsid mechanics is computationally challenging because direct Bayesian inference with dissipative particle dynamics (DPD) is prohibitively expensive. We employ a surrogate-accelerated Bayesian calibration workflow that combines deep neural network (DNN) surrogates, transitional Markov chain Monte Carlo sampling, and hierarchical regularization across EMB diameters. Using this framework, we develop two data-informed DPD models of commercial EMB agents, i.e., Definity and SonoVue, and perform inference of force field parameters based on published compression experiments for Definity and indentation experiments for SonoVue, each spanning three distinct diameters. The inferred posteriors show that key model parameters, such as the stretching stiffness and bending modulus, are consistently constrained by the available data. The presented methodology can be used to derive bespoke, data-informed models for a wide range of ultrasound contrast agents, including encapsulated gas vesicles, EMBs with diverse capsids consisting of lipids, proteins, or polymers, and functionalized with ligands. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13644 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13644v1 Announce Type: cross Abstract: Spin qubits have emerged as a leading platform for quantum information processing due to their long coherence times, small footprint, and compatibility with the existing semiconductor industry. We first provide an introduction to the different qubit implementations currently being investigated, including single electron-spin qubits, hole-spin qubits, donor qubits, and multispin encodings. We discuss how the confinement and strain present in semiconductor heterostructures produce addressable levels whose spin degree of freedom can be used to encode a qubit. A large emphasis is placed on reviewing the theoretical foundations and recent experimental demonstrations of proposed mechanisms for long-range coupling, including hybrid approaches based on circuit QED and Andreev qubits, as well as spin shuttling. Finally, we review a recent proposal for linking spin qubits using topological spin textures. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13358 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13358v1 Announce Type: cross Abstract: If an operator $H$ anticommutes with a chirality operator $\Gamma_*$ such that $\Gamma_*^2=1$, the null space of $H$ can be decomposed in a direct sum of two spaces having positive and negative chiralities, respectively. When both spaces are finite dimensional, one can define an index, $\mathrm{Ind}(\Gamma_*,H)$, as the difference of dimensions of these two spaces. The key issue is whether $\mathrm{Ind}(\Gamma_*,H)$ is topologically protected, i.e., whether it remains constant under smooth variations of the parameters and background fields entering $H$. For Hermitian Dirac operators, topological protection of the index is guaranteed by the Atiyah--Singer theorem. In this paper, by using the heat kernel methods, we show that $\mathrm{Ind}(\Gamma_*,H)$ is topologically protected also for non-hermitian operators $H$ as long as they are diagonalizable and satisfy some ellipticity conditions. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13339 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13339v1 Announce Type: cross Abstract: Hydroxyapatite (HAp) is the primary mineral component of various mineralized tissues in the human body, including bone and teeth, where it performs critical roles of structural support and load transmission. In the context of dental health, the two most crucial properties of HAp are mechanical stability, which ensures resistance to forces, and chemical stability, which preserves surface integrity in acidic environments. During early stages of human evolution, e.g. when teeth were used to crush uncooked food, mechanical stability was of paramount importance. However, with changes in diet and lifestyle, the principal origins of tooth damage and loss shifted towards bacterially mediated chemical attack, known as tooth decay, or caries. To enhance the chemical stability, ion doping has emerged as a particularly significant approach, and it lies at the focus of the present study. A Molecular Dynamics (MD) framework was developed to investigate the effects of ion doping on the chemical and mechanical stability of HAp and to identify optimal doping candidates. The framework combines conventional MD with Steered Molecular Dynamics (SMD), Thermodynamic Integration (TI) and uniaxial compression test simulations to provide comprehensive insights into the doping process. The findings revealed surface atoms as the most viable candidates for doping, as demonstrated by SMD and conventional MD simulations. Notably, TI calculations have identified magnesium ions as a better candidate among the ions considered here for enhancing the chemical stability of HAp. The results presented in this study offer valuable guidelines for synthesizing HAp-based substituent materials with properties tailored to meet the demands of modern dental applications such as implant coatings, enamel remineralization agents and restorative materials. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.14150 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.14150v1 Announce Type: new Abstract: Non-Hermitian band descriptions capture how loss, gain, and environmental coupling reshape quantum matter, yet most experimental tests rely on wave-based or dynamical probes. Here we establish a new equilibrium route to exceptional physics in Dirac materials: in the weakly non-Hermitian regime, the thermodynamic density of states and the quantum capacitance exhibit a universal equilibrium approach to the exceptional point. In our minimal non-reciprocal graphene model, the hopping imbalance reduces the Dirac velocity as $v_F=v\sqrt{1-\beta^2}$, implying that the low-energy density of states, the thermodynamic density of states, and the quantum capacitance all scale as $(1-\beta^2)^{-1}$ as $|\beta|\to 1^-$. Consequently, at charge neutrality the quantum capacitance remains linear in temperature but with a diverging prefactor, while the inverse response softens linearly on approaching the exceptional point. In a magnetic field, this manifests as a collapse of the Landau-level spacing and a corresponding crowding of thermally active levels. Complementarily, the biorthogonal Bloch states exhibit a Petermann factor $K=(1-\beta^2)^{-1}$, which isolates the irreducibly non-Hermitian effect of eigenvector non-orthogonality. These results identify quantum capacitance as an experimentally accessible bulk equilibrium probe of effective non-Hermiticity in Dirac materials. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13945 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13945v1 Announce Type: new Abstract: Kitaev chains realized in quantum dots coupled via superconducting segments provide a controllable platform for engineering Majorana zero modes (MZMs). In these systems, subgap states in the hybrid region mediate the effective coupling between quantum dots and determine the emergence of sweet-spots where MZMs are strongly localized. However, existing minimal treatments often oversimplify the mesoscopic hybrid region. We perform a full microscopic treatment of this hybrid segment, capturing the quasiparticle continuum and spin-split Andreev bound states (ABSs), and show that it fundamentally alters the minimal picture. We derive analytical expressions for the renormalized couplings and sweet-spot conditions, establishing a direct link between microscopic chain parameters and Majorana optimization and identifying experimentally relevant regimes for improved device performance. Critically, we find that parity-crossings of the ABS, marking the onset of an odd-parity spin-polarized regime in the segment, identify the optimal operating windows where MZMs are simultaneously well localized with a large gap to excited states. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13936 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13936v1 Announce Type: new Abstract: We study a Su-Schrieffer-Heeger chain coupled to a single mode photonic cavity. Considering an off-resonant regime we use the high-frequency expansion in order to obtain an effective fermionic Hamiltonian with cavity-mediated interactions. We characterize the effects of the cavity on topology in a finite size chain by studying three different markers adapted for interacting systems: correlation functions between edges in a chain with open boundary conditions, and a winding number based on the single-particle Green's function and bulk electric polarization via the many-body formula by Resta for a chain with periodic boundary conditions. There is excellent agreement between the winding number and polarization approaches to compute the phase diagram, with the presence of the edge states being confirmed through the calculations of the two-point correlation function. Our approach provides an alternative perspective on cavity-modified topological phases through a study of an effective interacting electronic Hamiltonian and complements methods that treat the full light-matter Hamiltonian directly. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13920 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13920v1 Announce Type: new Abstract: Nonlinear modal interactions in resonant systems govern a wide range of phenomena, with broad relevance across modern physics and engineering. Yet, experimentally determining the strength of nonlinear coupling in multimode resonators remains highly challenging. Here, we introduce a multi-tone spectroscopy method for identifying nonlinear coupling coefficients directly from experimental data. Our approach employs dual-tone excitation near selected resonances which, in combination with additional probing tones at higher-order modes, generates sideband responses associated with specific modal couplings. These spectral signatures are analyzed using an inverse reconstruction procedure to quantitatively determine the corresponding nonlinear coupling strengths in the frequency domain. Using this method, we determine ten pairwise nonlinear coupling parameters across five modes of highly tensioned nanostrings, enabling the reconstruction of fully experimental, device-specific nonlinear reduced-order models. Our experimentally derived models show excellent agreement with values obtained numerically using finite element based nonlinear reduced-order models. Our method is generic and can be used for the characterization of diverse modal and intermodal couplings in mechanical and hybrid resonant systems. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13893 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13893v1 Announce Type: new Abstract: Quantum geometry, a quantum mechanical quantity comprised of Berry curvature and quantum metric, describes the geometric structure of the electronic bands in solids. The correlation between nontrivial quantum geometry and quantum materials leads to new findings in condensed matter systems. Here we demonstrate that altermagnets, with spontaneously broken time-reversal (T)- half-lattice-translation and parity-time symmetry, host both T-odd and T-even quantum geometric quantities that simultaneously manifest themselves despite the vanishing net magnetization. Consequently, giant room-temperature third-order electrical transport responses with sizable quantum geometric contributions are observed in (101)-oriented RuO2 thin films, an altermagnetic candidate; in particular, the third-order Hall effect is intimately correlated with altermagnetic order and can serve as a promising tool for detecting the Neel vector. Our work not only supports the existence of altermagnetism in 8-nm-thick RuO2 thin films, but also shows altermagnets as a versatile platform for exploring quantum geometry and constructing quantum electronic and spintronic devices. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13760 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13760v1 Announce Type: new Abstract: Spin shuttling has crystalized as a powerful and promising tool for establishing intermediate-range connectivity in semiconductor spin-qubit devices. Although experimental demonstrations have performed exceptionally well on different materials platforms, the question of how to handle areas of low valley splitting in silicon during shuttling remains unresolved. In this work, we explore the possibility of utilizing the valley degree of freedom, particularly in regions of low valley splitting, to allow mobile spin qubits to be shuttled through an occupied stationary quantum dot, thereby leapfrogging over the stationary electron. This not only grants a more enriched mobility for shuttled electrons, as it opens new possible routing paths, but also enables the implementation of an entangling SWAP$^\gamma$ two-qubit gate operation in the process. Simulating this process for different sets of parameters, we demonstrate the feasibility of such an operation and offer a unique use case for otherwise precarious regions of a quantum processor chip and propose a possible extension to the set of possible operations for silicon spin qubit devices. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13729 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13729v1 Announce Type: new Abstract: Light-matter interactions are governed by conservation laws of energy and momentum. For harmonic generation in crystalline solids, energy conservation imposes that $m$ incoming photons with energy $\hbar \omega_0$ are combined to form one photon at energy $m\hbar \omega_0$. Linear momentum conservation governs phase matching, whereas angular momentum conservation connects the angular momentum carried by photons to the discrete rotational symmetry of the crystal lattice. As a consequence, circular harmonic generation exerts a torque on the lattice and, conversely, a macroscopic rotation of the crystal induces a nonlinear rotational Doppler shift. These cornerstone laws of nonlinear optics rely on macroscopic symmetry arguments, and therefore provide little insight into the microscopic origin of angular momentum transfer. Here we uncover a direct connection between angular momentum conservation in nonlinear optics and the electronic quantum geometry, by proving that the transferred angular momentum from light to the crystal is proportional to the local Berry curvature at one optical resonance. This relation is encoded in the nonlinear harmonic circular dichroism, which we measure experimentally in an atomically thin semiconductor. With this, we extend our understanding of nonlinear optics, and we establish a method for the all-optical control and read-out of the local Berry curvature. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13682 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13682v1 Announce Type: new Abstract: We investigate the emergence of charge waves and their temporal dynamics in one-dimensional Su-Schrieffer-Heeger (SSH) topological chains. Contrary to the conventional view that charge oscillations are suppressed in gapped topological systems with preserved chiral symmetry, we show that such oscillations can indeed occur. The general condition for an arbitrary oscillation period is analysed, and we find that the charge waves propagating along the chain do not depend on its topology, except at the edges, where both topological phases exhibit essential differences. In chains with inequivalent atoms within the SSH unit cell, we observe regular long-period sublattice oscillations that appear simultaneously with even-odd charge oscillations. Furthermore, we study the nonequilibrium dynamics in SSH chains. After a quench, the time evolution of the local density of states and charge occupancies exhibits clear dynamical fingerprints that distinguish topologically trivial and nontrivial phases. Our results establish that transient charge dynamics can distinguish topologically trivial and nontrivial phases in real time by detecting the presence of topologically-protected edge states. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13662 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13662v1 Announce Type: new Abstract: Tuning of gate-defined semiconductor quantum dots (QDs) is a major bottleneck for scaling spin qubit technologies. We present a deep learning (DL) driven, semantic-segmentation pipeline that performs charge auto-tuning by locating transition lines in full charge stability diagrams (CSDs) and returns gate voltage targets for the single charge regime. We assemble and manually annotate a large, heterogeneous dataset of 1015 experimental CSDs measured from silicon QD devices, spanning nine design geometries, multiple wafers, and fabrication runs. A U-Net style convolutional neural network (CNN) with a MobileNetV2 encoder is trained and validated through five-fold group cross validation. Our model achieves an overall offline tuning success of 80.0% in locating the single-charge regime, with peak performance exceeding 88% for some designs. We analyze dominant failure modes and propose targeted mitigations. Finally, wide-range diagram segmentation also naturally enables scalable physic-based feature extraction that can feed back to fabrication and design workflows and outline a roadmap for real-time integration in a cryogenic wafer prober. Overall, our results show that neural network (NN) based wide-diagram segmentation is a practical step toward automated, high-throughput charge tuning for silicon QD qubits. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13661 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13661v1 Announce Type: new Abstract: Photoabsorption in the low-energy region for C$_{60}$ and PTCDA molecular complexes is studied within linear response TDDFT. For the PBE, B3LYP and HSE exchange-correlation (xc) functionals the dependence of the accuracy of the exciton energy on the electron-hole separation is analyzed. Particular attention is paid to the charge-transfer (CT) excitons. The inclusion of non-local exchange using hybrid functionals increases the accuracy of calculations for short-range excitons, however, the accuracy of hybrid functionals decreases significantly for long-range excitons. Moreover, as the exciton radius approaches the "screening length"\ , the simpler PBE functional gives more accurate excitonic energies than the mentioned hybrid functionals. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13532 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13532v1 Announce Type: new Abstract: Symmetry-protected topological phases of matter, characterized by non-trivial band topology, are spectrally gapped and show non-trivial boundary phenomena. Here, we show that scattering states when interjected by an array of periodically modulated defects can result in emergent topological phases whose properties can be tuned by modulating the defect strengths. We dub this the Su-Schrieffer-Heeger network. We show that a scattering-matrix network model can capture the emergent symmetries and nontrivial winding of the quasienergy bands, which lead to distinct transport signatures and can be further periodically driven to realize a robust Thouless charge pump. We show that a microscopic lattice model embedded with a defect superlattice yields Bloch minibands that directly map to the network problem. We further verify that the physics we report is stable to disorder and point out concrete experimental solid-state platforms where it is readily realizable. Our work, in contrast to engineering atomic Hamiltonians, shows that defect engineering on metallic platforms can lead to emergent topological phases of quantum matter. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13527 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13527v1 Announce Type: new Abstract: Two-dimensional phononic crystals (PnCs) formed by a periodic array of holes in a suspended membrane have previously been used to coherently control thermal conductance at low temperatures by modifying the phonon dispersion, thereby altering the phonon group velocities and the density of states. Here, in contrast, we demonstrate that PnCs formed by a periodic array of Al pillars on an uncut \SiN membrane can also be used to achieve similar coherent control. We have measured and simulated the thermal conductance of four pillar-based PnCs with different lattice constants ranging from 0.3 to 5 $\mu$m at sub-Kelvin temperatures, showing a strong up to an order of magnitude reduction in thermal conductance compared to an unaltered membrane. For the larger lattice constants $> 1 $ $\mu$m, however, the experiments do not agree with the coherent theory simulations, which we interpret as a breakdown of coherence induced by increasingly effective diffusive scattering due to the roughness of the Al pillar surfaces. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13451 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13451v1 Announce Type: new Abstract: We predict the emergence of nontrivial topological magnon states in the skyrmionium lattice with zero topological charge. We propose the concept of weighted magnetic flux, which provides a clear physical picture for this anomalous phenomenon. We also map the skyrmionium lattice onto the Haldane model, offering an alternative framework for interpreting this. Our findings challenge the conventional wisdom that such states are linked to nonzero topological charge in skyrmion lattices, offering a new perspective in topological magnonics. To facilitate experimental validation, we propose two methods for preparing the skyrmionium lattice and calculate the induced magnon thermal Hall conductivity, which is a key indicator in transport measurements. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13445 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13445v1 Announce Type: new Abstract: Van der Waals heterostructures made from atomically thin transition metal dichalcogenides (TMD) and graphene have emerged as a building block for optoelectronic devices. Such systems are also uniquely poised to investigate interfacial coupling as well as photoinduced charge and energy transfer in the 2D limit. Recent works have revealed efficient photoluminescence quenching and picosecond transfer in TMD/graphene heterostructures. However, key questions regarding the transfer mechanisms remain. Here, employing time-resolved photoluminescence spectroscopy with 1~ps resolution in MoSe$_2$ monolayer directly coupled to a few-layer ``staircase-like'' graphene flake, we consistently observe an exciton transfer time of $\approx 2.5~\mathrm{ps}$ at cryogenic temperature that is marginally affected by the number of graphene layers. Remarkably, exciton transfer vanishes in samples consisting in an MoSe$_2$ monolayer separated from graphene by a thin dielectric spacer of hexagonal boron nitride, as soon as the spacer thickness reaches 1~nm. These results suggest that charge tunnelling processes govern exciton dynamics. Other mechanisms mediated the dipolar interactions (F\"orster-type energy transfer) have no measurable impact on bright excitons (with near-zero center of mass momentum) but may accelerate the relaxation of finite momentum ``hot'' excitons, leading to larger photoluminescence quenching than anticipated based on the measurements of the photoluminescence decay rates. Our work provides important insights into charge and energy transfer in van der Waals materials with direct implications for energy harvesting and funneling. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13364 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13364v1 Announce Type: new Abstract: Aluminum nitride (AlN)-based thin-film bulk acoustic wave resonators (FBARs) are promising compact platforms for 6G communications and quantum memory hardware, enabled by their integrable acoustic modes with high quality factors. However, temperature-dependent acoustic dissipation ultimately limits device performance. In this work, we fabricated a 16 GHz epitaxial AlN FBAR as a test platform, performed small-signal RF measurements from 6.5 K to 300 K, and developed a physics-based model to estimate the fundamental quality-factor limits of FBARs to cryogenic temperatures. The proposed model incorporates both intrinsic and extrinsic loss mechanisms, including an analytical anchor-radiation loss model for bulk acoustic wave resonators, rather than relying solely on finite-element simulations. Measured loaded quality factor (Q) decreases monotonically with temperature, from Qmax of approximately 1589 (Qf=24.79 THz) at 6.5 K to 363 at 294K (Qf=5.66 THz). This trend is consistent with the theoretical limit based on the resonator geometry and the chosen Metal-Insulator-Metal (MIM) stack. To demonstrate the generality of the physics-based framework, we further validate it by benchmarking against a 23 GHz high-overtone bulk acoustic resonator (HBAR) using previously reported data. The validated model provides a practical, transferable framework to interpret Q(T) limits in low-loss resonators by quantifying the temperature-dependent mechanisms that constrain Q, enabling the design of cryogenic microwave filter elements for superconducting quantum hardware. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.13337 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13337v1 Announce Type: new Abstract: The nitrogen-vacancy (NV) center in diamond enables optical initialization and readout of its electronic spin, forming the basis of a wide range of quantum sensing and metrology applications. A central challenge in such measurements is the coexistence of two charge states, NV- and NV0: While detection protocols rely on the spin-dependent properties of NV-, fluorescence from NV0 does not carry useful contrast and is typically removed as background, reducing the available signal. Here, we show that the origin of NV0 emission depends strongly on the excitation wavelength in nitrogen-containing diamond. Using ensembles of NV centers with varying nitrogen concentrations, we compare excitation at the NV0 zero-phonon line (ZPL) at 575 nm with the commonly used 532 nm. We find that excitation at 575 nm generates NV0 predominantly through spin-selective tunneling from the excited state of NV- to nearby nitrogen donors, such that the NV0 emission follows the spin polarization of NV-. As a result, the NV0 fluorescence contributes to the measurable spin contrast, allowing the full fluorescence signal to be used for detection. This result opens opportunities for improved sensitivity in NV-based sensing applications. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2603.15534 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2603.15534v2 Announce Type: replace-cross Abstract: Quantum annealing processors typically control qubits in unison, attenuating quantum fluctuations uniformly until the applied system Hamiltonian is diagonal in the computational basis. This simplifies control requirements, allowing annealing QPUs to scale to much larger sizes than gate-based systems, but constraining the class of available operations. Here we expand the class by performing analog-digital quantum computing in a highly-multiplexed, superconducting quantum annealing processor. This involves evolution under a fixed many-body Hamiltonian that, in the weak-coupling regime, is well-described by an effective XY model, together with arbitrary-basis initialization and measurement via auxiliary qubits. Operationally, this is equivalent to implementing single-qubit gates at the beginning and end of an analog quantum evolution. We demonstrate this capability with several foundational applications: single-qubit and two-qubit coherent oscillations with varying initialization and measurement bases, a multi-qubit quantum walk with fermionic dispersion in line with theory, and Anderson localization in a disordered chain. These experiments open the door to a wide range of new possibilities in quantum computation and simulation, greatly expanding the applications of commercially available quantum annealing processors. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2509.23977 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2509.23977v2 Announce Type: replace-cross Abstract: Ecological interactions can dramatically alter evolutionary outcomes in complex communities. Yet, the framework of population genetics largely neglects interactions from a species-rich community. Here, we bridge this gap by using dynamical mean-field theory to integrate community ecology into classical population genetics models. We show that ecological interactions result in emergent frequency-dependent selection between parents and mutants, characterized by a single parameter measuring the strength of ecological feedbacks. This result generalizes classical population genetics models to highly diverse communities and enables predictions of mutation outcomes in these eco-evolutionary settings. We derive an analytic expression for fixation probability that extends Kimura's formula and reveals that ecological interactions strongly suppress the fixation of moderately beneficial mutations. This suppression arises because frequency-dependent selection leads to prolonged coexistence between parent and mutant lineages, which acts as a barrier to fixation. The strength of these effects increases with effective population size and the number of open niches in the ecosystem. Our study establishes a framework for integrating ecological interactions into population genetics, showing that evolutionary outcomes can be predicted using simple models even in the presence of complex community feedbacks. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2601.04702 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2601.04702v2 Announce Type: replace Abstract: High-dimensional dynamical systems of interacting degrees of freedom are ubiquitous in the study of complex systems. When the directed interactions are totally uncorrelated, sufficiently strong and non-linear, many of these systems exhibit a chaotic attractor characterized by a positive maximal Lyapunov exponent (MLE). On the contrary, when the interactions are completely symmetric, the dynamics takes the form of a gradient descent on a carefully defined cost function, and it exhibits slow dynamics and aging. In this work, we consider the intermediate case in which the interactions are partially symmetric, with a parameter {\alpha} tuning the degree of non-reciprocity. We show that for any value of {\alpha} for which the corresponding system has non-reciprocal interactions, the dynamics lands on a chaotic attractor. Correspondingly, the MLE is a non-monotonous function of the degree of non-reciprocity. This implies that conservative forcing deriving from the gradient field of a rough energy landscape can make the system more chaotic. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.13843 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13843v1 Announce Type: cross Abstract: We developed a machine learning interatomic potential (MLIP) for Ge-rich GeSbTe alloys of interest for applications in phase change memories embedded in microcontrollers. The MLIP was generated by fitting with a neural network method a large database of energies and forces computed within density functional theory of elemental, binary, stoichiometric and non-stoichiometric ternary alloys in the Ge-Sb-Te phase diagram. The MLIP is demonstrated to be highly transferable to large regions of the phase diagram around the compositions included in the dataset. The MLIP is then exploited to simulate the crystallization with phase separation of three Ge-rich alloys on the Ge-Sb$_2$Te$_3$ and Ge- Ge$_2$Sb$_2$Te$_5$ tie-lines that correspond to the set process of the memory cell. The transformation on the ns time scale and at 600 K, comparable to the operation conditions of the memory, yields crystalline cubic GeTe slightly Sb-doped and amorphous GeSb and Ge. These metastable phases differ from the thermodynamically stable products and form due to kinetics effects on the short time span of the set operation in phase change memories. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.13511 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13511v1 Announce Type: cross Abstract: In many real-world problems, recovering sparse signals from underdetermined linear systems remains a fundamental challenge. Although $\ell_1$ norm minimization is widely used, it suffers from estimation bias that prevents it from reaching the Bayes-optimal reconstruction limit. Nonconvex alternatives, such as the log-sum penalty, have been proposed to promote stronger sparsity. However, maintaining their algorithmic stability is challenging. To address this challenge, we introduce an adaptive smoothing strategy within an approximate message passing framework to mitigate algorithmic instability. Furthermore, we evaluate the typical exact-recovery threshold for Gaussian measurement matrices using the replica method and state evolution. The results indicate that the adaptive method achieves exact recovery over a broader region than $\ell_1$ norm minimization, although metastable states hinder reaching the information-theoretic limit. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2602.23187 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2602.23187v2 Announce Type: replace Abstract: We report an extremely rich ground state phase diagram of two spin-1 Haldane chains frustrated with a three-site exchange and coupled by the antiferromagnetic Heisenberg interaction on a zig-zag ladder. A particular feature of the phase diagram is the extended quantum phase transition in the Ashkin-Teller universality class that separates the plaquette phase, which spontaneously breaks translation symmetry, and the uniform disordered phase. The former is connected to the Haldane phase, stabilized by large inter-chain coupling, via the topological Gaussian transition. Upon decreasing the inter-chain interactions, this intermediate disorder phase vanishes, giving place to a dimerized phase separated from the plaquette phase on one side via a non-magnetic Ising transition and from the Haldane phase on the other side by a topological weak first-order transition. Finally, in the limit of two decoupled chains, we recover a quantum critical point that corresponds to two copies of the Wess-Zumino-Witten $\mathrm{SU(2)}_2$ criticality with a total central charge $c=3$. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.13781 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13781v1 Announce Type: cross Abstract: We study prethermalization in time-independent quantum many-body systems on a $d$-dimensional lattice with an extensive local Hamiltonian $H=N+\varepsilon P$, in the regime where $\varepsilon \ll 1$. We show that the prethermalization time is exponentially large in $\varepsilon_0/\varepsilon$, where $\varepsilon_0$ is the ratio between an effective spectral gap width and the local norm of $P$. We prove also that for exponentially long times, there exist two quasi-conserved quantities up to exponentially small errors. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13639 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13639v1 Announce Type: cross Abstract: Heat transport exhibits distinct regimes ranging from ballistic propagation to diffusive relaxation, traditionally described by disparate theoretical frameworks. Here, we introduce a unified first-order operator formulation in which temperature and heat flux are treated as a coupled state vector, yielding a minimal dynamical closure of heat transport. The resulting generator is intrinsically non-Hermitian and gives rise to a spectral structure governed by an exceptional point that separates overdamped diffusion from underdamped wave-like propagation. In this framework, Fourier law emerges as a singular limit of a hyperbolic dissipative system, while the Cattaneo equation arises naturally as the minimal hydrodynamic closure of kinetic theory. We show that the exceptional point induces nonanalytic spectral transitions, nonmodal transient dynamics, and a breakdown of conventional modal decomposition. The theory further generalizes to anisotropic media, where direction-dependent exceptional surfaces enable intrinsic steering of heat flow. Our results establish a unified non-Hermitian dynamical framework for heat transport and reveal exceptional-point physics as a fundamental organizing principle underlying thermal dynamics across scales. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13852 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13852v1 Announce Type: new Abstract: We derive the asymptotic first passage time (FPT) distribution for space-dependent variable-order time-fractional diffusion, where the fractional exponent $\alpha(x)$ varies with position. For any sufficiently smooth $\alpha(x)$ on a finite domain with absorbing and reflecting boundaries, we show that the survival probability decays as $\Psi(t)\sim C\,t^{-\alpha_*}/(\ln t)^{\nu}$, where $\alpha_*$ is the minimum value of the fractional exponent and $\nu$ is determined by the location and shape of the minimum. For a constant fractional exponent $\nu=0$ and this provides a theoretical prediction that can identify spatially heterogeneous anomalous transport in experiments. We validate the theory against exact Laplace-space solutions and Monte Carlo simulations for linear and nonlinear profiles of $\alpha(x)$. Condensed_Matter/cond-mat.stat-mech_(Statistical_Mechanics) https://arxiv.org/abs/2604.13099 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13099v1 Announce Type: cross Abstract: We develop a Melnikov framework for the Kuramoto Sivashinsky (KS) equation under weak deterministic and stochastic forcing. By treating KS as an infinite dimensional dynamical system, we derive a Melnikov functional that measures splitting of stable and unstable manifolds of a homoclinic orbit. Periodic forcing leads to phase dependent transverse intersections, while stochastic forcing produces random manifold splitting characterized by a variance determined by the adjoint solution. This provides a geometric mechanism linking invariant manifold theory to spatiotemporal chaos in dissipative partial differential equations. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.13790 Thu, 16 Apr 2026 00:00:00 -0400 arXiv:2604.13790v1 Announce Type: new Abstract: Ferromagnetic elastic slender structures offer the potential for large actuation displacements under modest external magnetic fields, due to the magneto-mechanical coupling. This paper investigates the phase portraits of the Hamiltonian governing the three-dimensional deformation of inextensible ferromagnetic elastic rods subjected to combined terminal tension and twisting moment in the presence of a longitudinal magnetic field. The total energy functional is formulated by combining the Kirchhoff elastic strain energy with micromagnetic energy contributions appropriate to soft and hard ferromagnetic materials: magnetostatic (demagnetization) energy for the former, and exchange and Zeeman energies for the latter. Exploiting the circular cross-sectional symmetry and the integrable structure of the governing equations, conserved Casimir invariants are identified and the Hamiltonian is reduced to a single-degree-of-freedom system in the Euler polar angle. Analysis of the resulting phase portraits reveals that purely elastic and hard ferromagnetic rods undergo a supercritical Hamiltonian Hopf pitchfork bifurcation, whereas soft ferromagnetic rods exhibit this bifurcation only within a restricted range of the magnetoelastic parameter, $0<\tilde{K}_{dM}<1/8$. Both helical and localized post-buckling configurations are analyzed, and the corresponding load-deformation relationships are systematically characterized across a range of loading scenarios. Localized buckling modes, corresponding to homoclinic orbits in the Hamiltonian phase space, are constructed numerically. In contrast to the purely elastic case, the localized configurations of soft ferromagnetic rods exhibit non-collinear extended straight segments, a geometrically distinctive feature arising directly from the magnetoelastic coupling. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2603.18843 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2603.18843v2 Announce Type: replace-cross Abstract: The geometry of Fermi sea hosts a unique form of quantum topology that governs the conductance quantization of metal and is characterized by the Euler characteristic $\chi_F$, offering a new perspective in the study of topological quantum matter. Here, we discover that characterizing Fermi sea topology solely by $\chi_F$ is insufficient: Fermi seas with identical $\chi_F$ can exhibit fundamentally different fine-grained topological structures that cannot be connected without a Lifshitz transition. To encode this hidden structure, we introduce a structural resolution factor that captures the fine-grained Fermi sea topologies beyond $\chi_F$, revealing the deeper topological information within the Fermi sea. Considering the attractive Hubbard interaction of electrons on Fermi surfaces, we further demonstrate that the resulting topological superconducting phases can inherit the fine-grained Fermi sea topology of their parent metallic bands, with differences in these structures giving rise to anomalous gapless boundary states at the interface between two metal/superconductor heterojunctions. This work opens an avenue for understanding the topological richness of Fermi sea. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2510.20804 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2510.20804v2 Announce Type: replace-cross Abstract: Motivated by recent experiments on rhombohedral stacked multilayer graphene and the observation of the anomalous Hall effect in a spontaneous spin-valley polarized quarter metal state, we calculate the anomalous Hall conductivity for this system in the presence of two types of impurities: weak and dense as well as sparse and strong. Our calculation of $\sigma_{xy}$ is based on the Kubo-Streda diagrammatic approach. In a model with Gaussian disorder applicable to weak dense impurities, this involves all non-crossing diagrams (intrinsic, side-jump and Gaussian skew-scattering contributions) and additionally diagrams with two intersecting impurities, X and $\Psi$, representing diffractive skew-scattering processes. A "Mercedes star" diagram (non-Gaussian skew scattering) is furthermore included to treat in the case of strong, sparse impurities. We supplement our asymptotically exact analytical solutions for an isotropic model without warping effects by semi-numerical calculations accounting perturbatively for warping, which plays a crucial role in the low-energy band structure. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2505.06155 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2505.06155v2 Announce Type: replace-cross Abstract: Superconducting resonator parametric amplifiers are potentially important components for a wide variety of fundamental physics experiments and utilitarian applications. We propose and realise an operating scheme that achieves amplification through the use of non-degenerate pumps, which addresses two key challenges in the design of parametric amplifiers: non-continuous gain across the amplification band and pump tone removal. We have experimentally demonstrated the non-degenerate pumping scheme using a half-wave resonator amplifier based on NbN thin-film, and measured a peak gain of 26 dB and 3-dB bandwidth of 0.5 MHz. The two non-degenerate pump tones were positioned ~10 bandwidths above and below the frequency at which peak gain occurs. We have found the non-degenerate pumping scheme to be more stable compared to the usual degenerate pumping scheme in terms of gain drift over time, by a factor of 4. This scheme also retains the usual flexibility of NbN resonator parametric amplifiers in terms of reliable amplification in a ~4 K environment, and is suitable for cross-harmonic amplification. The use of pump tones at different frequencies allows phase-sensitive amplification when the signal tone is degenerate with the idler tone. A gain of 23 dB and squeezing ratio of 6 dB were measured. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.12742 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12742v1 Announce Type: new Abstract: We investigate the Josephson coupling between two superconducting electrodes connected by a ferromagnetic racetrack hosting a Bloch-like domain wall (DW). We show that the interplay between superconductivity and the DW leads to highly non-trivial spatial distributions of the supercurrent, including the formation of current loops and a strong sensitivity to the DW position and orientation. We further demonstrate that the Josephson critical current $I_c$ can be efficiently controlled by the DW position along the racetrack, exhibiting pronounced variations and tunable $0$--$\pi$ transitions. These results provide clear design principles for superconducting racetrack devices and establish domain walls as a viable control element for readout schemes in racetrack memory architectures. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.12695 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12695v1 Announce Type: new Abstract: We theoretically investigate charge transport in a junction between a conventional superconductor and a V$_2$O-based altermagnet exhibiting distinctive spin-split quasi-one-dimensional Fermi surfaces. The altermagnet is described by a microscopically motivated six-orbital model that incorporates sublattice degrees of freedom associated with both V and O sites. Based on calculations performed under various boundary conditions, we demonstrate the robust emergence of specular Andreev reflection with a distinctive spin polarization. Furthermore, we propose an efficient multiterminal setup to detect this specular Andreev reflection through nonlocal conductance measurements. Our results establish V$_2$O-based altermagnets as a promising platform for realizing spin-resolved Cooper pair splitting, which is essential for generating energy-entangled electron pairs. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2604.12367 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12367v1 Announce Type: new Abstract: Li$_2$AuH$_6$ and Li$_2$AgH$_6$ have been proposed as promising candidates for high-temperature superconductors under ambient pressure. While previous studies confirm the dynamic stability of these two thermodynamically unstable systems, their kinetic stability remains to be verified. In this work, we use path integral molecular dynamics simulations to examine the kinetic stability of Li$_2$AuH$_6$ and Li$_2$AgH$_6$ under ambient pressure. We find both compounds are kinetically unstable. Li$_2$AgH$_6$ undergoes lattice collapse, whereas Li$_2$AuH$_6$ retains a stable fluorite-type Li-Au sublattice, but hydrogen atoms partially dimerize into molecules and diffuse within the host lattice. Using the stochastic path-integral approach, which is a nonperturbative approach applicable to systems with diffusive atoms, we investigate the superconductivity of Li$_2$AuH$_6$ in this state. We predict a superconducting transition temperature of 22 K, well below earlier predictions, due to the low density of states at the Fermi level caused by the collapse of hydrogen sublattice and hydrogen dimerization. Condensed_Matter/cond-mat.supr-con_(Superconductivity) https://arxiv.org/abs/2507.08080 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2507.08080v2 Announce Type: replace Abstract: Isometric tensor product states (isoTPS) generalize the isometric form of the one-dimensional matrix product states (MPS) to tensor networks in two and higher dimensions. Here, we introduce an alternative isometric form for isoTPS by incorporating auxiliary tensors to represent the orthogonality hypersurface. We implement the time evolving block decimation (TEBD) algorithm on this new isometric form and benchmark the method by computing ground states and the real time evolution of the transverse field Ising model in two dimensions on large square lattices of up to 1250 sites. Our results demonstrate that isoTPS can efficiently capture the entanglement structure of two-dimensional area law states. The short-time dynamics is also accurately reproduced even at the critical point. Our isoTPS formulation further allows for a natural extension to different lattice geometries, such as the honeycomb or kagome latice. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2505.12639 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2505.12639v4 Announce Type: replace Abstract: The origin of electron-boson interactions is central to understanding high-$T_c$ superconductivity in cuprates. While phonons and magnetic fluctuations are widely considered as candidates for mediating electron pairing, the role of charge fluctuations -- one of the fundamental electronic degrees of freedom -- remains unclear. Here, we investigate the electronic structure of the electron-doped cuprate Nd$_{2-x}$Ce$_x$CuO$_4$ using angle-resolved photoemission spectroscopy and angle-resolved inverse photoemission spectroscopy, which reveal the occupied and unoccupied states, respectively. We identify emergent spectral features on both occupied and unoccupied states that are consistent with excitations driven by quantum charge fluctuations. The results obtained in this study offer direct experimental insight into charge fluctuations in cuprates, thereby paving the way towards clarifying their fine electronic structure and the mechanism of high-$T_c$ superconductivity. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12472 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12472v1 Announce Type: new Abstract: The Hofstadter butterfly (HB) and mobility edges (MEs) are hallmark phenomena of quasiperiodic systems, yet their interplay remains elusive. Here, we demonstrate their convergence within a tilt-induced quasiperiodic potential on a square lattice, giving rise to a ``mobility-edge-embedded Hofstadter butterfly'' (MEE-HB). This potential is generated by aligning a periodic potential at an angle relative to the lattice axes--a configuration readily accessible in optical lattice experiments. Using a tight-binding model, we show that the MEE-HB manifests as a fractal energy splitting pattern hosting MEs that separate extended and localized states. Our Harper-like equation shows that the fractal pattern originates from 1D quasiperiodic potentials, while MEs stem from effective long-range hopping. Notably, the MEE-HB exhibits a fractal dimension of 0.8--1.0, significantly exceeding the 0.4--0.6 range of the standard butterfly, indicating a denser spectral set. Our findings establish tilt-induced potentials as a versatile platform for exploring the interplay between fractal structures and localization. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.12732 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12732v1 Announce Type: new Abstract: We investigate quantum percolation in a honeycomb lattice with site dilution and random spin-orbit coupling. Using exact diagonalization combined with finite-size scaling analysis, we study the metal-insulator transition, extracting the quantum percolation threshold $p_q$, and the correlation-length exponent, $\nu$. In the absence of spin-orbit coupling, we find that $p_q$ remains finite and demonstrate that the quantum threshold is significantly higher than the classical site-percolation threshold $p_c$ of the honeycomb lattice. When spin-orbit coupling is present, the spectral statistics exhibit a crossover from the Gaussian orthogonal ensemble to the Gaussian symplectic ensemble, reflecting the change in symmetry class. Simultaneously, the quantum percolation threshold shifts systematically to lower occupation probabilities, indicating that the spin-orbit coupling favors delocalization. For sufficiently strong spin-orbit coupling, $p_q$ tends to saturate, while the critical exponent approaches the expected one of the two-dimensional symplectic universality class. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.12759 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12759v1 Announce Type: new Abstract: We study localization and flat-band formation in lattices generated by repeated edge inflation of square, honeycomb, and triangular parent lattices. Replacing each bond by a finite tight-binding chain produces several distinct classes of flat bands: chain-induced flat bands at the eigenenergies of the inserted chains, symmetry-protected zero-energy flat bands in bipartite edge-inflated lattices, and nearly flat junction bands near the spectral edges for sufficiently long chains. We analyze these mechanisms for ordered Lieb-$L$, super$^{L}$honeycomb, and super$^{L}$triangular lattices, and examine their response to bond disorder, site disorder, random magnetic flux, and randomness in the inflation process itself. While bond and site disorder broaden most flat bands, the zero-energy chiral band and the junction-induced flat bands remain robust under certain perturbations. Remarkably, substantial flat-band features also persist in randomly edge-inflated graphs, even in the absence of translational symmetry. In particular, the number of zero-energy states is found to be well estimated by the matching deficiency $N-2\nu(G)$, indicating that local tree-like structure continues to control the low-energy nullity. These results identify edge-inflated lattices as a broad class of systems in which geometry alone generates robust localization in both ordered and random settings. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.10861 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.10861v1 Announce Type: cross Abstract: The computational demands of deep learning motivate the investigation of alternative approaches to computation. One alternative is physical neural networks~(PNNs), in which learning and inference are performed directly via physical processes. Stochastic PNNs arise when the underlying neurons are realized by the dynamics of a stochastic activation switch. Here we propose novel electronic and photonic stochastic neurons. The electronic realization is implemented by single-electron tunneling through a quantum dot. The photonic realization is implemented via a single-photon source driving one of two modes coupled via a controllable beam-splitter-like interaction. In the electronic case, the charge state of the quantum dot forms the basis for the stochastic neuron, whereas in the photonic case the occupation of the undriven mode serves as the basis for the stochastic neuron. Training of stochastic PNNs is performed with models of stochastic neurons, as well as with coherently-driven, single-photon detector stochastic neurons previously introduced. Several training strategies for MNIST handwritten digit classification have been investigated using single-hidden-layer stochastic PNNs, including varying the number of trials in each layer to control forward pass stochasticity and employing either true probability or empirical outputs in the backward pass to evaluate their influence on gradient estimation. We show that when empirical outputs are used in the backward pass, the network achieves more than 97\% test accuracy with few trials per layer. Despite the simplicity of the model architecture, high test accuracy is maintained in the presence of a high degree of noise and model uncertainty. The results demonstrate the potential of embracing stochastic PNNs for deep learning. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.12151 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12151v1 Announce Type: cross Abstract: Modern distributed networks, notably transformers, acquire a remarkable ability (termed `in-context learning') to adapt their computation to input statistics, such that a fixed network can be applied to data from a broad range of systems. Here, we provide a complete mechanistic characterization of this behavior in transformers trained on a finite set $S$ of discrete Markov chains. The transformer displays four algorithmic phases, characterized by whether the network memorizes and generalizes, and whether it uses 1-point or 2-point statistics. We show that the four phases are implemented by multi-layer subcircuits that exemplify two qualitatively distinct mechanisms for implementing context-adaptive computations. Minimal models isolate the key features of both motifs. Memorization and generalization phases are delineated by two boundaries that depend on data diversity, $K = |S|$. The first ($K_1^\ast$) is set by a kinetic competition between subcircuits and the second ($K_2^\ast$) is set by a representational bottleneck. A symmetry-constrained theory of a transformer's training dynamics explains the sharp transition from 1-point to 2-point generalization and identifies key features of the loss landscape that allow the network to generalize. Put together, we show that transformers develop distinct subcircuits to implement in-context learning and identify conditions that favor certain mechanisms over others. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.12347 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12347v1 Announce Type: cross Abstract: Self-healing is the ability of a wave packet to spontaneously restore its spatial profile after scattering. As an emergent feature of non-unitary dynamics, it has attracted significant interest in non-Hermitian physics. Here, we systematically investigate how stochastic noise influences edge self-healing. Counterintuitively, we find that noise can constructively enhance this dynamical process. Weak noise prolongs the self-healing window by aligning the finite-time Lyapunov exponent of the reference state with the maximum imaginary part of the energy spectrum. Remarkably, strong noise universally stabilizes asymptotic profile recovery across the entire spectrum by inducing an effective non-unitary drift-diffusion dynamics. We analytically elucidate these distinct mechanisms using a general finite-time Lyapunov exponent analysis, complemented by a dedicated perturbation theory for the strong-noise regime. Our results provide concrete guidance for realizing robust non-Hermitian dynamics in realistic noisy environments. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.12464 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12464v1 Announce Type: cross Abstract: We present an introductory review of nonergodic dynamics in interacting many-body quantum systems, focusing on the phenomenon of many-body localization (MBL). We describe aspects of MBL and summarize the evidence for a crossover from the ergodic to the MBL regime in finite systems, using the paradigmatic XXZ model as an example. We then broaden the scope to other models to illustrate the generality of the phenomenon. We briefly touch on the largely unexplored relation between MBL and quantum computing. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.12939 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12939v1 Announce Type: cross Abstract: In Hermitian impurity scattering, each isolated late-time exponential is the fingerprint of a bound state. We show that this correspondence breaks down in non-Hermitian bands. For a single impurity in a non-Hermitian lattice, the late-time signal is controlled by isolated complex frequencies selected by the analytic continuation of the Green's function relevant to real-time dynamics, which we term dynamical poles (DPs). DPs need not coincide with static bound states: one may appear without any bound-state counterpart, while a static bound state may be dynamically invisible. The remainder of the signal is an incoherent background set by complex continuum edges. Our results establish that the real-time analytic structure of the Green's function, not the static eigenvalue problem alone, organizes non-Hermitian impurity scattering. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.06741 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.06741v2 Announce Type: replace Abstract: The $\mathbb{Z}_N$ cluster-state wavefunction, a paradigmatic example of symmetry-protected topological (SPT) order with $\mathbb{Z}_N \times \mathbb{Z}_N$ symmetry, is expressed in various equivalent ways. We identify the projector-based scheme called the $P$-representation as the efficient way to express cluster and dipolar cluster state's wavefunctions. Employing the restricted Boltzmann machine scheme to re-write the interaction matrix in the $P$-representation in terms of neural weight matrices allows us to develop the neural quantum state (NQS) and the matrix product state (MPS) representations of the same state. The NQS and MPS representations differ only in the way the weight matrices are split and grouped together in a matrix product. For both $\mathbb{Z}_N$ cluster and dipolar cluster states, we derive in closed form the weight function $W(s,h)$ that couples physical spins $s$ to hidden variables $h$, generalizing the previous construction for $Z_2$ cluster states to $\mathbb{Z}_N$. For the dipolar cluster state protected by two charge and two dipole symmetries, the procedure we have developed leads to the tensor product state (TPS) representation of the wavefunction where each local tensor carries three virtual indices connecting a given site to two nearest neighbors and one further neighbor. We benchmark the resulting TPS construction against conventional MPS representation using density-matrix renormalization group simulations and argue that the TPS could offer a more efficient representation for some modulated SPT states. As a by-product of the investigation, we generalize the previous $Z_2$ matrix product operator construction of the Kramers-Wannier (KW) operator to $\mathbb{Z}_N$ and interprets it as the dipolar generalization of the discrete Fourier transform on $\mathbb{Z}_N$ variables. The new interpretation naturally explains why the KW map is non-invertible. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2411.19112 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2411.19112v3 Announce Type: replace-cross Abstract: Quantum neural networks promise to extend the power of machine learning into the quantum domain, with potential applications ranging from automatic recognition of quantum states to the control of quantum devices. However, their physical implementation and training remain challenging. In particular, the backpropagation algorithm that underpins the efficiency of classical neural networks cannot generally be applied to large quantum systems, as nonlinear quantum dynamics are not efficiently simulable. Instead, variational quantum circuits typically rely on parameter-shift rules or sampling-based gradient estimation. Here we propose a bosonic quantum neural network based on parametrically coupled Gaussian modes. Although the underlying quantum dynamics are linear, nonlinear output features are generated through Fock-basis measurements. Because Gaussian evolution can be efficiently simulated in the Heisenberg representation, the system admits gradient-based optimization by differentiating a classical model of the dynamics, while the forward evolution itself could be implemented on quantum hardware. This hybrid approach enables end-to-end training of physically meaningful parameters without requiring gradient extraction from the experimental device. Such architectures are naturally compatible with circuit quantum electrodynamics platforms featuring tunable parametric couplers, as well as integrated photonic systems with engineered $\chi$(2) or $\chi$(3) nonlinearities. Our results demonstrate that linear bosonic networks combined with nonlinear measurement provide a scalable and trainable route toward experimentally realizable quantum neural networks. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2511.20163 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2511.20163v2 Announce Type: replace-cross Abstract: We recently showed that the two-dimensional Ising spin glass allows for a line of renormalization group fixed points which explains properties observed in numerical studies. We observe that this exact result corresponds to enhancement to a one-generator continuous internal symmetry. This finally explains why no finite temperature transition to a spin glass phase is observed in two dimensions. In more than two dimensions, instead, the continuous symmetry can be broken spontaneously and yields a spin glass order parameter which, for fixed temperature and disorder strength, takes continuous values in an interval. Such a feature is shared by the order parameter of the known mean field solution of the model with infinite-range interactions, which corresponds to infinitely many dimensions. Condensed_Matter/cond-mat.dis-nn_(Disordered_Systems_and_Neural_Networks) https://arxiv.org/abs/2604.11984 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11984v1 Announce Type: new Abstract: Nonlinear light-matter interaction and, in particular, high-harmonic generation (HHG) are fundamentally interesting and frequently discussed as versatile probes of quantum materials with potential for optical information processing applications. Meanwhile, there has also been significant progress in graphene-based multilayer systems to engineer interesting band structures and boost correlation effects. Motivated by the successful demonstration of HHG in graphene, we here study this effect in rhombohedral stacks of $n$ layers of graphene, a recent very prominent representative of correlated multilayer graphene systems. We show how the chiral Bloch states of the valleys of this system crucially affect the HHG. The "winding" of the Bloch states scales linearly with $n$, just like the dominant harmonic order. The location of the strongest quantum geometry in momentum space on a ring of finite radius is shown to be imprinted on the time-dependent momentum distribution at the beginning of the strong laser pulse. We further demonstrate that the presence of an interaction-induced splitting of the two valleys leads to a complex interplay of the opposite chiralities of the two valleys, directly visible in the $n$ dependence of the circular dichroism. We also analyze the impact of doping and identify a quantity that tracks the net chirality of the occupied states. Our findings show that rhombohedral graphene constitutes a promising platform for exploring rich nonlinear optical phenomena. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12264 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12264v1 Announce Type: new Abstract: The advent of van der Waals (vdW) heterostructures has enabled formation of bespoke materials with atomic precision, where numerous quantum and topological phenomena have already been discovered. This atomic-layer tunability, however, comes at a cost: individual 2D layers must be picked up, moved, and placed in a deterministic manner while keeping their interfaces atomically clean. Recent advances in machine learning and robotics place even stronger emphasis on the deterministic aspect of vdW assembly. Current polymer-based transfer methods satisfy neither the determinism nor cleanliness requirements. To this end, solutions are needed where adhesion can be dynamically and deterministically controlled without leaving organic contamination. Here, we present a polymer free transfer technique employing thin muscovite (mica) crystals. Temperature control over mica adhesion enables deterministic pick-up, stacking, and release of 2D materials, while their crystalline, inorganic nature ensures pristine interfaces and suppresses strain. Fully compatible with existing fabrication workflows, this approach enables the assembly of demanding vdW heterostructures, including those with exposed conductive layers, moir\'e superlattices and suspended membranes. Our method represents a promising strategy for vdW heterostructure fabrication toward its automatization. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12275 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12275v1 Announce Type: new Abstract: We compute the magnetoelectric conductivity of a semimetal hosting an ideal gapped nodal ring (GNR) in three distinct planar-Hall configurations, in the simultaneous presence of an external electric field $\boldsymbol{E}$, a magnetic field $\boldsymbol{B}$, and a strain-induced axial pseudomagnetic field $\boldsymbol{B}_5$. The latter arises from a nonuniform lattice deformation and couples to antipodal points on the toroidal Fermi surface with opposite signs, reflecting its chiral nature. Extending our earlier analysis to include $\boldsymbol{B}_5$, we demonstrate how its vortex-like field lines -- co-aligned with the Berry curvature (BC) and orbital magnetic moment (OMM) -- imprint qualitatively distinct signatures on the conductivity tensor. In particular, this alignment causes the dot product of $\boldsymbol{B}_5$ with the BC or OMM-induced quantities to be angle-independent on the Fermi surface, generating a nonvanishing integral linear-in-$B_5$, which is not possible for isotropic nodal points harbouring BC-monopoles. We show that a part of the planar-Hall conductivity in the first set-up remains completely immune to strain, providing a strain-insensitive internal reference for topological transport. Our explicit analytical expressions offer concrete and experimentally testable predictions for identifying strain-induced signatures in transport measurements on GNR materials. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12295 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12295v1 Announce Type: new Abstract: We show that excitons forming between moir\'e flat Chern bands possess a substantial electric dipole moment comparable to the moir\'e lattice parameter times the elementary charge ($\sim10^2$ Debye). At a hole filling factor of one in twisted MoTe$_2$, the dipole moment of the lowest-energy exciton branch develops in-plane helical texture in momentum space from the intrinsic Berry curvature of electron and hole. By solving the Bethe-Salpeter equations, we demonstrate that an out-of-plane displacement field induces a Frenkel-to-Wannier exciton transition, accompanied by a reversal of the dipole texture helicity. The resulting attractive exciton dipole-dipole interactions lead to quadrupolar biexcitons that can be probed via two-photon spectroscopy. Our findings establish band topology as a tunable knob to engineer exciton dipole moments and pave the way to manipulate many-body interactions in the terahertz regime. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12366 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12366v1 Announce Type: new Abstract: The development of compact and highly sensitive microwave detectors compatible with complementary-metal-oxide-semiconductor (CMOS) processes is an active research area but remains a major challenge in microwave technology. Spin-torque diodes (STDs) are emerging nanoscale spintronic devices capable of surpassing the theoretical thermodynamic sensitivity limits of Schottky diodes. However, their practical use in compact systems is limited by the need of external antennas or probes. Here, we demonstrate a magnetoelectric (ME) spin-torque microwave detector that monolithically integrates an ME antenna with a magnetic tunnel junction (MTJ). The device directly converts wireless electromagnetic signals into a DC output at sub-microwatt power levels, achieving a sensitivity greater than 90 kV/W, a noise equivalent power of 3 pW*Hz^-0.5, and a compact footprint of 0.4 mm^2. This performance is due to the nonlinear coupling between incoherent magnetization dynamics, driven by a DC current in the MTJ, and the combined effects of the microwave voltage and strain generated by the ME antenna under incident electromagnetic waves. We further show that this design is scalable, enabling the co-integration of an ME antenna with an array of MTJs. A detector incorporating four MTJs, for example, exhibits a sensitivity exceeding 400 kV/W. This work paves the way for a new generation of highly sensitive, compact and scalable microwave detectors that combine ME antennas and spintronic diodes. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12510 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12510v1 Announce Type: new Abstract: We report gate-controlled quantum-dot transport in a trilayer MoSe2 device that combines a graphite back gate beneath the active region, a separate global gate for conductive access regions, and local top finger gates. In the low-backgate regime, bias spectroscopy shows regular Coulomb-blockade diamonds characteristic of single-dot transport. As backgate is increased, additional low-bias structure develops beyond a simple single-dot pattern, indicating that the electrostatic landscape is reshaped and that a second dot becomes active in transport. In the higher-backgate regime, plunger-gate tuning and two-gate measurements establish a gate-reconfigurable double-dot configuration with two non-equivalent dots whose relative alignment and interdot coupling evolve with gate voltage. These results indicate that trilayer MoSe2 supports electrically reconfigurable single- and double-dot transport in the present device architecture. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12544 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12544v1 Announce Type: new Abstract: We investigate electron paring in two-dimensional electron systems mediated by the vacuum fluctuations of a quantized magnetic flux generated by the inductor of an LC resonator. The interaction induces long-range attractive interactions between angular momentum states which lead to pairing in a broad class of materials with critical temperatures of few Kelvin or even higher, depending on the field-covered area. The induced state is a pair-density wave topological chiral superconductor. The proposed platform in circuit QED environment offers a tunable promising tool for engineering electron interactions in two-dimensional systems to create new quantum phases of matter. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12605 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12605v1 Announce Type: new Abstract: A time-dependent theory for the interactions between spatially separated lossy cavities in a homogeneous background medium using quantized quasinormal modes (QNMs) is presented. The cavities interact via a bath of traveling photons, described by non-bosonic operators that are orthogonal to the open-cavity QNMs. The retarded (i.e., time-delayed) inter-cavity dynamics are fully described by system-bath correlation functions, in which the emission from one cavity appears as the input field for another. Coupling between quantum emitters (described as two-level systems), placed inside a cavity or embedded in an external medium, and the electromagnetic field (cavity modes and bath photons) is included in the theory, which gives rise to both bath-mediated and QNM-mediated interactions between the emitters. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12614 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12614v1 Announce Type: new Abstract: Moir\'e superlattices are generally assumed to act only at the interface where lattice mismatch or twist occurs. Here, we study charge transport in large-angle helical twisted trilayer graphene, where interlayer tunneling is strongly reduced. When only the top monolayer graphene is aligned with hBN, the electronic response reorganizes into a moir\'e-modulated monolayer and a remaining twisted bilayer graphene subsystem. Despite the absence of any explicit structural moir\'e in the twisted bilayer, we observe satellite-like features in its electronic response that run parallel to the primary spectrum and are locked to the density scale of the hBN/graphene moir\'e. These findings indicate that a moir\'e potential may not be confined to its structural interface and can, through electrostatic coupling, influence a spatially separated Dirac subsystem even in the absence of strong interlayer tunneling. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12664 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12664v1 Announce Type: new Abstract: We investigate the optical response of a conduction electron in a helically twisted mesoscopic medium containing a screw dislocation and a uniform torsional background, in the presence of an axial magnetic field and an Aharonov--Bohm flux. We show that the coupling between longitudinal motion and the geometric background produces an effective in-plane confinement, allowing bound states to emerge without the need for an external radial potential. Exact analytical solutions are obtained for the energy spectrum and radial wave functions, and these results are used to evaluate linear and third-order nonlinear absorption, changes in the refractive index, the photoionization cross section, and the oscillator strength. The combined action of torsion, magnetic field, and topological defect increases the interlevel spacing, compresses the radial electronic distribution, and breaks the dynamical symmetry between opposite angular-momentum channels, leading to strongly asymmetric and state-resolved optical spectra. Under intense optical excitation, the nonlinear contribution can overcome linear absorption, driving the system into a negative-absorption regime and enabling geometry-controlled optical gain. These results establish torsion and defect engineering as effective tools for tuning confinement, resonant energies, and selective amplification in mesoscopic nanophotonic platforms operating in the mid-infrared and terahertz ranges. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12701 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12701v1 Announce Type: new Abstract: We propose a mechanism of supercurrent-induced phonon angular momentum in mixed parity superconductors and s-wave superconductors with spin orbit coupling. We derive analytical expressions of phonon angular momentum induced by the supercurrent by perturbative calculation. The physical interpretation of this effect is also discussed. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12726 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12726v1 Announce Type: new Abstract: Altermagnets represent a novel category of magnetic materials characterized by zero net magnetization yet featuring spin-split band structures, and they demonstrate distinctive orbital-spin locking phenomena. Commencing from the minimal multi-orbital tight-binding Hamiltonian of d-wave altermagnets, we conduct an analysis of the general formulas for the third-order injection and shift currents. These currents are solely determined by the quantum metric and quantum connection, being free from Berry curvature contamination. In the ideal scenario where the $\delta$-bond hopping $V_\delta$ approaches zero ($V_\delta = 0$), we derive closed-form analytical solutions for the third-order photoconductivities. For the general situation with a finite value of $V_\delta$, we present a perturbative analytical solution within the limit of $V_\delta \ll V_\pi$, and this solution is verified through numerical calculations. Our research establishes a comprehensive theoretical description of the third-order optospintronic responses in d-wave altermagnets based on a microscopic model. Moreover, it offers a viable approach for the experimental observation of pure quantum geometric effects. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12810 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12810v1 Announce Type: new Abstract: Quantum thermodynamics addresses the dynamics of heat flow in quantum devices driven out of equilibrium. Although mesoscopic circuits at low temperatures provide a flexible platform to explore this dynamics, experimental studies are wanting because thermal timescales in nanodevices are often too fast. Here we engineer and investigate with noise thermometry a mesoscopic thermal circuit where heat flows between electron, phonon and nuclear systems can occur on slower timescales. The central constituent of this device is a micrometer-scale metallic island electrically connected to large cold electron reservoirs through two to four ballistic quantum Hall channels, a component frequently used for exploring stationary thermal currents. We uncover a two-step thermalization process specific to the mesoscopic scale, involving a fast initial temperature step followed by a much slower rise extending over minutes. This observation is quantitatively accounted for by the balance between heat flows through electronic quantum channels, to cold phonons, and to the nuclear spins in the metallic island. The disclosed mesoscopic thermalization takes a step into the field of quantum thermo-\emph{dynamical} phenomena, highlighting their distinctive nature on a central constituent of quantum circuits. The implications for the thermal engineering of nanodevices include the thermal characterization of exotic states at high magnetic field. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12866 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12866v1 Announce Type: new Abstract: We study the coupling between spin excitations and acoustic waves in bilayers of CrSBr, an ambiently stable 2D magnetic material. We demonstrate that a strong dependence of inter-layer exchange coupling on strain makes possible the resonant generation of magnons by an acoustic wave. It is shown that the parameters of the generation, in particular the resonant frequency, can be tuned by an external magnetic field, which makes CrSBr a promising platform for spintronics applications. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12943 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12943v1 Announce Type: new Abstract: The Wiedemann--Franz law, which determines the universality of the ratio of thermal conductivity to electrical conductivity, is studied in the hydrodynamic electron transport regime, where electron--electron scattering predominates over scattering by disorder. In this case, the different relaxation of electric and thermal currents can lead to a violation of the Wiedemann--Franz law, which is expected to be even more pronounced in mesoscopic electron systems. This paper reports the propagation of hot electrons in a GaAs hydrodynamic narrow channel, studied using micrometer-resolution photoluminescence thermometry. A temperature dependence of the Lorenz number was obtained, indicating a violation of the Wiedemann--Franz law. The important role of narrow constrictions in this violation was also demonstrated, and theoretical arguments are presented. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12950 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12950v1 Announce Type: new Abstract: In a hybrid system where two quantum dots (QDs) are coupled to a conventional $s$-wave superconductor, Poor Man's Majorana modes (PMMs) have been proposed. Existing theories often idealize the superconductor (SC) as a bulk system or an infinitely long chain, or treat it as another quantum dot with proximity-induced superconductivity, while experiments employ superconducting segments of finite length. Here, we model the SC as a finite-length 1D chain and treat the QDs and SC on equal footing. We obtain the conditions for the existence of PMMs, valid for arbitrary SC length and applicable to arbitrary tunneling strengths and magnetic fields. We find that the number of PMMs is highly sensitive to the SC length: it oscillates between zero and two with a period set by the Fermi wavelength ($\sim1\,\text{\AA}$), while four PMMs appear in the long-SC limit where the effective coupling between the two QDs becomes negligible. We further demonstrate that the PMMs that are separately localized at the two ends of the hybrid system do not exist in the finite-length case. Consequently, only nearly localized PMMs can be identified when the magnetic field is strong enough. In this way, the generalized `sweet spot' of the practical system can be found. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12174 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12174v1 Announce Type: cross Abstract: Hyperbolic phonon polaritons (HPPs) are coupled oscillations of anisotropic lattice vibrations and electromagnetic fields that confine the latter to the nanoscale, enabling novel nano-polaritonic devices. While HPPs have been identified in multiple layered materials, achieving advanced control and manipulation - particularly polariton canalization for unidirectional energy flow - often necessitates complex device fabrications or crystal modifications. Here we visualize and elucidate the properties of in-plane hyperbolicity in alpha-V2O5, a layered compound with a highly anisotropic permittivity tensor. We show unidirectional Poynting-vector propagation of polaritons in alpha-V2O5 without additional treatments. Combined with theoretical modeling, our infrared nano-imaging studies unveil a novel form of polariton canalization, with its dispersion contour continuously tunable by the incident light frequency. Additionally, we provide a theoretically calculated permittivity phase diagram for tailoring polaritonic wavefronts. These findings suggest that the metal-oxide alpha-V2O5 holds great promise for on-demand light canalization and control at the nanoscale. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12313 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12313v1 Announce Type: cross Abstract: Superconducting diodes enable dissipationless directional transport, yet achieving electrical tunability and scalability remains a major challenge for circuit-level integration. Here, we demonstrate an electrothermal-switch superconducting diode in which a gate-controlled nanoscale hotspot dynamically breaks inversion symmetry in a superconducting nanowire. This mechanism gives rise to two coexisting nonreciprocal transport regimes-one associated with a nonreciprocal superconducting-to-normal transition and the other with ratchet-like vortex dynamics-both originating from the same electrothermal-switch process. The diode exhibits efficiencies up to 42% and 60% for the two regimes, respectively, and can be electrically switched on, off, or reversed in polarity in situ by applying a small gate current. These capabilities enable programmable superconducting circuits that realize electrically reconfigurable full-wave and half-wave rectification. The lithography-compatible design, high performance, and gate-controlled functionality establish a scalable platform for programmable superconducting electronics and hybrid quantum systems. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12571 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12571v1 Announce Type: cross Abstract: Two-dimensional ferromagnets with strong perpendicular magnetic anisotropy exhibit magnetic order down to the monolayer thickness, beneficial for energy-efficient spintronic devices. In this work, molecular beam epitaxy has been employed to realize controlled Ni-doping in Fe$_{3}$GeTe$_{2}$ (FGT) epitaxial films. MBE not only enables a large-scale growth of 2D films, but also allows a precise control over thickness and doping. X-ray diffraction and scanning transmission electron microscopy (STEM) reveal the formation of high-quality epitaxial films of pristine and Ni-doped FGT on graphene via van der Waals (vdW) epitaxy. Integrated differential phase contrast STEM images further provide in-depth information on Ni substitution and intercalation into the vdW gaps. Ni incorporation in doped films results in the shrinking of both in-plane and out-of-plane lattice parameters. Superconducting Quantum Interference Device, Hall, and X-ray magnetic circular dichroism measurements were utilized to probe the ferromagnetic properties of the films. Due to both Ni substitution and intercalation into the vdW gaps for Ni-doped FGT films, we observed a suppression of PMA and a drastic reduction in the Curie temperature down to 50 K. Our density functional theory based calculations of structural and magnetic properties further supports and provide deep insights into the variations of magnetic exchange interaction parameters and atom-projected magnetocrystalline anisotropy energies due to Ni doping to understand the experimental observations. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.12583 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12583v1 Announce Type: cross Abstract: Being motivated by recent synthesis of a monolayer of gold, named goldene, from the nano-laminated ternary ceramic phase of Ti3AuC2, we are proposing two phases of goldene viz. goldene-I and goldene-II as anode material for Lithium-Ion batteries using first principles study. This innovative goldene-I monolayer, composed of triangular motifs of gold atoms, exhibits remarkable properties owing to its unique geometric configuration and intrinsic stability. In contrast, a theoretical structure known as goldene-II, featuring a combination of triangular and hexagonal motifs, has been proposed. This structure possesses intrinsic, periodically distributed pores among Au atoms and demonstrates structural integrity and mechanical robustness, even under lithium adsorption. The electronic band spectra and projected density of states reveal the metallic nature of both phases of goldene. Electrochemical evaluations reveal that goldene-II offers favorable lithium-ion adsorption energies, efficient charge transfer, and volumetric capacities. Goldene-I achieves a volumetric capacity of 0.713 Ah/cm3, while goldene-II reaches 0.783 Ah/cm3, confirming its high suitability for lithium storage volumetric capability. Moreover, goldene-I has an ultra-low barrier height of 15 meV, which supports rapid lithium-ion transport. Condensed_Matter/cond-mat.mes-hall_(Mesoscale_and_Nanoscale_Physics) https://arxiv.org/abs/2604.11850 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11850v1 Announce Type: new Abstract: In this study, surface-enhanced Raman scattering (SERS) and density functional theory (DFT) calculations were combined to investigate the SERS spectra of Ln-citrate complexes (Ln: Tb, Dy, Ho, Er, Tm, Yb, and Lu) under 488 and 532 nm excitation. Peak assignment was supported by simulated SERS spectra calculated with an optimized DFT method using large-core effective core potentials. The main bands near 935, 1060, 1315, and 1485 cm-1 were assigned to (C-COO-) + (CH2), (CH2) + (C-O -- Ln), sym(COO-) + (CH2), and asym(COO-) + (CH2), respectively. Relative peak intensities were evaluated by normalizing the bands near 935, 1060, and 1485 cm-1 to that near 1315 cm-1. The ratios I_935/I_1315 and I_1485/I_1315 generally increased from Dy-citrate to Lu-citrate, whereas the I_1060/I_1315 ratio decreased. These trends were observed under both excitation wavelengths. The decrease in relative SERS peak intensity of the 1060 cm-1 band is attributed to stronger Ln-O interaction and reduced polarizability change, whereas the increases of the 935 and 1485 cm-1 bands are likely related to changes in local electronic distribution and effective symmetry sensitivity. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.11906 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11906v1 Announce Type: new Abstract: Strongly bound excitons dominate the optical response in many van der Waals semiconductors, yet distinguishing between the different microscopic processes governing exciton dissociation remains challenging. Using time- and angle-resolved photoemission spectroscopy (TR-ARPES), we independently track exciton and band-edge carrier populations in bulk ReSe$_{\text{2}}$ under resonant excitation. By studying the fluence dependence and polarization-controlled exciton density dependence of the exciton dissociation process, we distinguish between competing processes and identify exciton photoionization as the microscopic dissociation mechanism. These results establish a population-resolved strategy for resolving exciton-to-carrier conversion pathways in strongly excitonic materials. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.11957 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11957v1 Announce Type: new Abstract: Self-driving laboratories promise to accelerate materials discovery. Yet current automated solid-state synthesis platforms are limited to ambient conditions, thereby precluding their use for air-sensitive materials. Here, we present A-Lab for Glovebox Powder Solid-state Synthesis (A-Lab GPSS), a robotic platform capable of synthesizing and characterizing air-sensitive inorganic materials under strict air-free conditions. By integrating an agentic AI framework into the A-Lab GPSS platform, we structure autonomous experimental design through abductive and inductive reasoning. We deploy this platform to explore the vast compositional space of lithium halide spinel solid-state ionic conductors. Across a synthesis campaign comprising 352 samples with diverse compositions, the system explores a broad chemical space, experimentally realizing 72% of the 171 possible pairwise combinations among the 19 metals considered in this study. Over the course of the campaign, the fraction of compositions exhibiting both good ionic conductivity (> 0.05 mS/cm) and high halide spinel phase purity increases from 1.33% in the first 75 agent-proposed samples to 5.33% in the final 75. Furthermore, by inspecting the AI's reasoning processes, we reveal distinct yet complementary discovery strategies: abductive reasoning interrogates abnormal observations within already explored regions, whereas inductive reasoning expands the search into broader, previously unvisited chemical space. This work establishes a scalable platform for the autonomous discovery of complex, air-sensitive solid-state materials. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12451 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12451v1 Announce Type: new Abstract: Laser material processing has emerged as a versatile and indispensable tool in various industries, including manufacturing, healthcare, and materials science. However, the interaction of a lasers with surfaces is highly dependent on a large number of factors, including properties of the laser source such as pulse duration, wavelength and pulse form, as well as properties of the material such as surface roughness, heat capacity and thermal conductivity. Therefore, the optimization of laser texturing processes in regards to specific target geometries while maintaining texture quality and process efficiency is a time consuming task that requires experienced operators with expert knowledge of the process and its components. The complex and nonlinear relationships between the various process, laser and material parameters and the resulting surface topography or functionality are challenging to model analytically. Therefore, the fabrication of large numbers of different parameter variations are typically required to enable empirical modeling and process optimization. Machine learning offers a promising approach to overcoming these challenges, particularly when the interrelations between process parameters are not well understood. It enables effective process optimization, surface property prediction, and automated monitoring-tasks that previously required expert knowledge. This chapter demonstrates the application of machine learning to Laser Surface Texturing techniques. Using algorithms such as neural networks and random forests, surface roughness can be predicted based on laser parameters and material data. This facilitates faster process optimization, reduces experimental effort, and enables predictive visualization - all while maintaining high accuracy. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12522 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12522v1 Announce Type: new Abstract: The integration of high-thermal-conductivity diamond films onto silicon carbide (SiC) substrates offers a promising pathway for thermal management in high-power electronic devices. Here, we investigate the depth-dependent thermal conductivity of a ~5 {\mu}m-thick diamond film grown on SiC by hot-filament chemical vapor deposition (HFCVD) using square-pulsed source (SPS) thermometry. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) reveal pronounced grain coarsening from the nucleation interface to the film surface. By combining frequency-dependent thermal penetration with a depth-resolved thermal transport model, we quantitatively reconstruct the thermal conductivity profile. The thermal conductivity increases sharply from ~60 W m^(-1) K^(-1) near the nucleation region to ~200 W m^(-1) K^(-1) at the surface, directly reflecting the underlying microstructural evolution. These results provide a physically grounded understanding of graded heat transport in HFCVD diamond and offer practical guidance for engineering diamond-based thermal management layers for next-generation power devices. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12531 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12531v1 Announce Type: new Abstract: We report a phenomenological theory for the kinetic arrest (KA) of a first-order phase transition, taking the Mott metal-insulator transition in $V_2O_3$ as a test case. By defining a order parameter $\phi$ related to the monoclinic distortion of the high temperature metallic and mapping its Time-Dependent Ginzburg-Landau (TDGL) dynamics onto a disorder-influenced Imry-Wortis landscape, we derive a universal transcendental condition for the mechanism of the kinetic arrest. We demonstrate that epitaxial substrate-induced clamping in (001)-oriented $V_2O_3$ thin films elevates the elastic activation barriers, trapping the high-symmetry corundum phase down to 4.2~K. This structural suppression of the insulating state robustly explains the observed hysteretic $V$-$I$ switching a hallmark of memristive behaviour. Our work identifies a "Mott-Glass" as a structurally arrested non-equilibrium state in the strained thin-film of V$_2$O$_3$. Our work provides a predictive framework for engineering strain-tuned neuromorphic synapses. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12609 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12609v1 Announce Type: new Abstract: LiGa$_5$O$_8$ in a spinel type structure has recently been claimed to be an unintentional p-type ultra-wide-band-gap oxide semiconductor. While previous computational work did not yet identify the origin of p-type doping and in fact predicted insulating behavior by compensation of deep acceptors by shallow donors, defect characterization in terms of its optical signatures remains important. Rather than focusing on thermodynamics transition levels, as in earlier work, this present paper focuses on the vertical transitions in a defect configuration diagram of defects in different charge states, representing absorption and emission processes involving carrier capture/emission from/to band edges. In addition, the structural relaxation of several native defects is revisited by allowing for more complex symmetry-breaking distortions in an effort to reconcile conflicting results in the previous literature. Special attention is given to the Li vacancy because it is the shallowest native acceptor. For this defect, the previously reported transition levels are revised on the basis of symmetry-breaking relaxations. The structural relaxations, band structures, and densities of states are compared between the symmetry-broken polaronic and symmetry-conserving non-polaronic states. Finally, we also study carbon impurities, which are likely to originate from growth methods involving organic precursors. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12612 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12612v1 Announce Type: new Abstract: Recrystallized tungsten (W) samples were irradiated by 20 MeV self-ions at 1350 K to peak damage doses in the range of 0.001-2.3 dpa. The irradiation-induced defects were then decorated with deuterium (D) by a gentle D plasma exposure ($<5$ eV/D, $5.6 \times 10^{19}$ $\text{D} / (\text{m}^2 \text{s})$) at 370 K. The D depth profiles in the samples were measured using $\rm D(^{3}He,p)\alpha$ nuclear reaction analysis. The maximum trapped D concentration evolves differently with the damage dose compared with the previously studied irradiations at 290 K and 800 K. At the damage doses below 0.1 dpa, the D concentrations are lower than those after the irradiation at 800 K. At higher damage doses, the D concentrations exceed the 800 K values and reach 1.7 at.% at 2.3 dpa, showing no clear tendency towards saturation. Transmission electron microscopy revealed the presence of nm-sized voids in the samples irradiated at 1350 K, in contrast to the ones irradiated at 290 K and 800 K. Thermal desorption spectroscopy (TDS) indicates that the dominant D trapping sites are different compared to the irradiations at 290 K and 800 K. Reaction-diffusion simulations show that the TDS spectra can be described by assuming that D is trapped as $\rm D_2$ gas in the void volume and as D atoms at the void surface. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12636 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12636v1 Announce Type: new Abstract: An anomalous Hall effect (AHE) in antiferromagnetic (AF) systems with no net magnetization is of considerable interest for both fundamental physics and spintronic applications. Of particular interest is the two-dimensional van der Waals antiferromagnet FeTe that has an unusual fully magnetically compensated bicollinear AF structure and exhibits pronounced Kondo interaction leading to strong band renormalization. Here, we investigate the AHE in epitaxial FeTe thin films grown by molecular beam epitaxy. A large anomalous Hall conductivity is exhibited below the Neel temperature (T_N ~ 60 K) and, strikingly, becomes nonlinear at high fields within a narrow temperature window around 49 K, deviating from conventional AHE scaling behavior versus its longitudinal conductivity. Linear fits reveal a pronounced negative peak in the intercept, accompanied by a field-induced canted magnetic moment. The AHE responses are related to the Berry curvature derived from FeTe's topological band structure, highlighting the intricate interplay between topology, magnetism, and electronic transport. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12670 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12670v1 Announce Type: new Abstract: The response of Ni-Cr alloys to exposure to molten chloride and fluoride salts is typically characterized by Cr dealloying with the formation of a Cr-depleted bi-continuous porous subsurface layer. The exact mechanism behind the loss of Cr over distances unattainable by lattice diffusion alone is still debated. To address this question, two different surface finishes, namely electropolished and sanded, of a Ni-30Cr alloy were exposed to LiCl-KCl-2wt% EuCl3 eutectic salt at 500 {\deg}C for 96 hours. In the absence of fast diffusion pathways, dissolution occurred layer by layer and was kinetically controlled by Ni dissolution, as observed over the grain interiors of the electropolished sample. Grain boundaries were subject to diffusion-induced grain boundary migration (DIGM), leading to the formation of pure Ni islands above grain boundaries. This overall behavior contrasted with the sanded surface response that was characterized by several micrometer deep interconnected porosity and complete Cr depletion. DIGM of the dense grain boundaries created by recrystallization of the sanded surface was responsible for the observed sub-surface microstructure. This work unequivocally establishes DIGM as a key mechanism in alloy molten salt corrosion, and microstructure as a decisive contributor to an alloy's corrosion response. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12680 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12680v1 Announce Type: new Abstract: Chromium-based materials with complex lattice geometries provide an important platform for investigating correlated electronic and magnetic states. However, Cr-based compounds with unusual crystal geometries are still rarely reported. Here, we report a new Cr-based compound, Cs$_4$Cr$_7$Te$_{10}$, featuring interwoven Cr and Te sublattices that can be viewed as reconstructed networks derived from Archimedean 3.4.6.4 tiling and the kagome lattice, respectively. Transport measurements reveal the semiconducting nature in Cs$_4$Cr$_7$Te$_{10}$. Magnetization measurements show a weak anisotropy between H//b and H//ac planes, and uncover an anomaly near 130 K that is insensitive to the applied magnetic fields. Specific-heat measurements further confirm this transition, indicating its bulk thermodynamic nature. The associated entropy change is as small as 0.41 J mol^-1 K^-1, ruling out a structural phase transition and pointing to a possible electronic and/or magnetic phase transition. These results provide a new route for designing complex crystal geometries and exploring their associated emergent phenomena. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12702 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12702v1 Announce Type: new Abstract: Controlling magnetic phases in two-dimensional systems, where charge transport is highly sensitive to real-space spin inhomogeneities, is central to understanding emergent magnetic states in reduced dimensions. In this context, thickness-dependent magnetotransport provides access to irreversible magnetic processes that are not captured by reversible transport or bulk magnetization alone. Here we report an extensive study of hysteretic magnetoresistance in single-crystalline nanoscale thin flakes of the layered antiferromagnet MnBi2Te4. The multi-step hysteresis exhibits a pronounced non-monotonic dependence on thickness and displays nontrivial angular anisotropy. The transport signatures rule out surface-dominated magnetism and simple bulk metamagnetic transitions as the primary origin. We argue that the magnetic irreversibility is possibly governed by domain wall pinning and de-pinning processes within a spatially non-uniform magnetic landscape. These results suggest that reduced dimensionality is a key driver of magnetic irreversibility in MnBi2Te4. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12728 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12728v1 Announce Type: new Abstract: Single-crystalline perovskite oxide membranes provide a powerful platform to access physical properties that are inaccessible in bulk crystals and substrate-clamped thin films. Within this context, the deliberate fabrication of tailored corrugations provides a reliable mean to impose local curvature enabling deterministic modulation of functional properties. Here, we demonstrate controlled topographic patterning in (00l)-oriented La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO) membranes with thicknesses ranging from 4 to 100 nm where they spontaneously form sinusoidal wrinkles with thickness-dependent periodicity and amplitude. The wrinkle morphology directly modulates membrane stiffness and generates exceptionally large local strains exceeding 5\% with strain gradients approaching $\sim$ 2.5 x 10$^{7}$ m$^{-1}$ in the thinnest membranes. These extreme deformations suppress antiferrodistortive octahedral rotations and stabilize polar distortions, evidencing a curvature-driven symmetry transformation. The surface potential variation reinforces the formation of wrinkled-induced polar patterns being strongly modulated with thickness. The variation of Mn oxidation state from $\sim$ 3.2+ to $\sim$ 2.85+ provides a direct chemical signature of a thickness-controlled electronic transition. These results demonstrate that corrugation-induced strain gradients in oxide membranes with different thicknesses can drive coupled structural, nanomechanical and electronic transformations, offering a singular route to engineer their functional states for next-generation electronic devices. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12730 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12730v1 Announce Type: new Abstract: Linear complexions are stable defect states that form along dislocations and recent experiments have demonstrated strengthening effects exceeding classical precipitation hardening predictions, motivating a detailed study of nanoscale strengthening mechanisms. Here, molecular dynamics simulations in Al-Cu and Ni-Al face-centered cubic alloys are used to demonstrate distinct plasticity mechanisms associated with linear complexions. Both nanoparticle array and platelet array complexions exhibit appreciable strengthening. In addition to direct interactions with the particles, stress field modification in nearby regions can restrict dislocation motion as well. Finally, the relative particle-dislocation orientation is found to have a large effect, with the strongest resistance observed when the dislocation stress field aligns with the original complexion nucleation condition. As a whole, these findings provide mechanistic insight into the strengthening observed experimentally and establish design principles for linear complexion-induced strengthening in structural alloys. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12734 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12734v1 Announce Type: new Abstract: 2D ferromagnets offer valuable insights into the fundamentals of magnetism and stimulate the progress of ultracompact spintronics. The demand for seamless integration of the materials with the Si technology, particularly helpful to their applications in nanoelectronics, draws attention to 2D magnetic silicides. MnSi is a prominent silicide hosting magnetic phases with unconventional properties; however, little is known about magnetic states of MnSi at the 2D limit. Here, we explore the magnetism of ultrathin films of MnSi on silicon, down to a single monolayer. Angle-resolved photoemission spectra suggest exchange splitting of MnSi bands. Magnetization measurements confirm that the ferromagnetic state in MnSi is rather robust with respect to the number of monolayers. Thick metallic films demonstrate the anomalous Hall effect and negative magnetoresistance; however, as the number of monolayers drops below 3, MnSi becomes an insulator. Most importantly, the ferromagnetism of ultrathin MnSi films acquires a 2D character, as its effective Curie temperature depends on weak magnetic fields. The present study establishes MnSi monolayers as 2D ferromagnets that can find potential applications in silicon-based spintronics. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12764 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12764v1 Announce Type: new Abstract: The magnetic field from a uniformly magnetised, rectangular prism is known exactly, which is the basis for a large number of micromagnetic simulations. Here we derive an analytical solution for the field from a periodically repeating infinite array of prisms aligned end-to-end, which becomes exact on the center axis in the limit of infinitesimally thin prisms. Using the same method we derive the on-axis field for a one-dimensional array of point dipoles. We validate the obtained results numerically and furthermore compare with the common macrogeometry approach and more recent uniform magnetisation method, demonstrating an excellent convergence rate for the novel method. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12786 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12786v1 Announce Type: new Abstract: Prospective spintronic memory and logic devices will benefit from the negligible stray field and ultrafast magnetic dynamics inherent to antiferromagnets [1]. However, realizing isothermal, nonvolatile,and deterministic switching of antiferromagnetic states remains a key challenge [2, 3]. Here,we propose a piezomagnetic writing scheme in triangular Mn3Ir-based memory cells, with readout achieved via the exchange bias effect. Our approach enables deterministic and nonvolatile switching of the antiferromagnetic states, which exhibit exceptional robustness against external perturbations.The switching mechanism is ascribed to piezomagnetic effect of Mn3Ir combined with the interfacial Dzyaloshinskii-Moriya interaction at the antiferromagnet-ferromagnet interface. This scheme overomes the speed limitations imposed by conventional isothermal methods based on isothermal crystallization mechanism [4]. Our findings highlight the potential of piezomagnetic effects in designing advanced spintronic devices, providing an efficient pathway for manipulating antiferromagnetic states and developing energy-efficient memory technology. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12824 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12824v1 Announce Type: new Abstract: All-optical generation of pure spin current -- the flow of spin in the absence of a corresponding charge flow -- relies on a symmetry based compensation of valley charge. The 2d $d$-wave altermagnets, ideal spintronics materials due to a very low spin-orbit coupling, possess a magnetic point group and highly anisotropic valley manifolds that would appear to preclude such current compensation, excluding them as materials for the ultrafast generation of pure spin current. Here we show that infra-red valley excitation combined with a THz pulse envelope allows the generation of large and nearly 100\% pure spin currents in the altermagnet Cr$_2$SO. Our approach is based on a valley selection rule coupling linearly polarized light to spin opposite valleys, along with the intrinsic momentum shift that a co-occurring THz pulse imbues a valley spin excitation with. These results thus provide a practical and all-optical route to the generation of pure spin current in $d$-wave 2d altermagnets, opening a route to lightwave control of spin in an environment with very low intrinsic spin mixing. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12828 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12828v1 Announce Type: new Abstract: We report the temperature-dependent synchrotron based X-ray diffraction analysis of NASICON type Na$_3$FeCr(PO$_4$)$_3$ sample, which undergoes a symmetry-lowering structural transition from a monoclinic ($C2/c$) phase with long-range Na-vacancy order to a rhombohedral ($R\bar{3}c$) phase with statistical disordered Na ions. The [FeCr(PO$_4$)$_3$] polyanionic framework remains essentially unchanged, confirming that the transition is governed by redistribution of the Na sublattice rather than by reconstruction of the host framework. The structural evolution is accompanied by a discontinuous increase in the $c$-axis and the unit-cell volume, reflecting the progressive depopulation of the Na(1) sites and transfer of Na ions toward the Na(2) sublattice. The temperature dependence of superstructure intensity found to deviate from mean-field critical behavior, instead, the experimental evolution is accurately captured by a sigmoidal phase-fraction model. The calorimetric measurements show that the enthalpy change for the first transition around 350~K is significantly larger than that of the anomaly around 445 K, indicating the dominant configurational rearrangement of Na ions occurs within the lower-temperature interval. Overall, the diffraction and calorimetric results demonstrate that Na ordering proceeds through an order-disorder transition involving intermediate Na configurations and a finite coexisting regime. The quantitative correlation between Na-vacancy ordering, lattice strain, and symmetry lowering reveals the central role of configurational interactions within the Na conduction channels in governing the phase stability of NASICON-type materials. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12979 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12979v1 Announce Type: new Abstract: Comparison of the measured spectral emission properties of single-crystal Cu(001) and W(111) photocathodes to established photoemission theories reveal evidence for an additional one photon emission process predominantly affecting electron emission near and below the photoemission threshold. This additional photoemission process is postulated to be due to a momentum-resonant Franck-Condon mechanism mediated by inelastic Umklapp electron scattering. An initial first-principles simulation of this emission process (involving the electron thermal effective mass, the inelastic electron mean free path at the vacuum level, and the number of Fermi surfaces in the metal), when combined with a direct one-step band emission model, is consistent with the measured spectral dependencies of both the quantum efficiency and mean transverse energy of electron photoemission from the two single-crystal metal photocathodes. Condensed_Matter/cond-mat.mtrl-sci_(Materials_Science) https://arxiv.org/abs/2604.12722 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12722v1 Announce Type: new Abstract: We study THz emission from ferromagnet / nonmagnetic material (FM/NM) spintronic nanostructures in which the $Ni_xCu_{1-x}$ alloy with different $x$ is used as an FM, an NM, or both layers. The stoichiometric composition of the NiCu alloys standing at two positions (we denote it as [FM] or [PM]) is chosen so that it is ferromagnetic at room temperature in the case it is used as the FM layer, and is paramagnetic at room temperature for the NM layer. Besides, we choose the nickel ratio $x$ close to each other for both [FM] and [PM] types of the alloy (the difference is only $10\%$). We show that although NiCu[PM] does not contain heavy metal it acts as an effective converter of spin current into the electric one in our structure showing only 2.8 times smaller efficiency than Pt. Besides, the NiCu[FM] alloy, despite having quite small Curie temperature (approximately $65 ^\circ C$), acts as an effective spin source having the efficiency only 2 times smaller than Co in similar structures. This shows up the importance of boundary matching in the spintronic THz sources. Our NiCu-based THz sources reveal a possibility of effective thermally induced control of emission of THz radiation due to a unique combination of high emission rate and relatively small Curie temperature. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.12008 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12008v1 Announce Type: cross Abstract: The interest to foster plasmonic applications at energies in the ultra-violet, has escalated research initiatives in clusters of unconventional plasmonic materials like aluminum and indium,for which the surface-plasmon resonance appears above the ionization potential. Naturally, the quantum mechanical description calls for the incorporation of the ionization process, thereby making the ab initio calculations challenging. We present a robust approach within the time-evolution formalism of the time-dependent density-functional theory to calculate surface plasmon resonance in the continuum of metal clusters. Using the much studied Al$_{13}^-$ as a system of reference, we show that accurate description of the continuum and of the ionization of the cluster allow to capture a broad surface-plasmon in the UV. Application of this approach in aluminum clusters has given the size-dependent evolution from discrete spectral features in Al$_{6}$ to the surface-plasmon in larger clusters in the deep ultra-violet. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.12450 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12450v1 Announce Type: cross Abstract: We analytically describe the dynamically separated $\mathbb{Z}_{2}$ skin channels (wavepacket evolutions) under periodic boundary condition (PBC) in non-Hermitian systems with anomalous time-reversal symmetry (ATRS), by combining the semiclassical worldline perspective with an enhanced understanding of skin effects. These channels, tied to the initial state and relevant symmetries, exhibit individually exponential-dominated time evolution in momentum space, where their amplitude maxima evolve toward the dominant momenta. In real space, they circulate around the one-dimensional (1D) chain, tracing semiclassical worldlines. Such circulations imply quantum revivals and dynamical quantum phase transitions (DQPTs) regardless of any wavepackets' phase interference, with the latter showing scale-dependent behavior, a feature distinct from conventional DQPTs. This work rigorously demonstrates our previous findings on worldline windings and the winding-control mechanism, confirming that the core physics is shared with the ordinary skin effect. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.12682 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12682v1 Announce Type: cross Abstract: Observing the structure of quantized vortices can provide evidence for the pairing nature of a superfluid or superconductor and pinpoint its order parameter. Spin-triplet superfluid $^3$He supports a variety of vortices, calculated and identified so far in bulk fluid. We show numerically that the vortex core in $^3$He is strongly altered near a surface, resulting in a structure inhomogeneous along the vortex line. The effect is asymmetric with respect to the relative orientation of the core order parameter anisotropy axis and the surface normal. In a wide range of external conditions, the vortex structure at the surface is found to be completely different from that in bulk. The effect originates from the combination of spin-orbit interaction in triplet pairing with the symmetry breaking by the surface. As an implication, surface-limited vortex core observations in a triplet-candidate system may not reflect the bulk structure. We propose an experimental verification of the effect by measuring a transition in the vortex structure in thin slabs of superfluid $^3$He-B. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2506.08618 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2506.08618v4 Announce Type: replace-cross Abstract: AI is transforming scientific research by revealing new ways to understand complex physical systems, but its impact remains constrained by the lack of large, high-quality domain-specific datasets. A rich, largely untapped resource lies in non-Hermitian quantum physics, where the energy spectra of crystals form intricate geometries on the complex plane -- termed as Hamiltonian spectral graphs. Despite their significance as fingerprints for electronic behavior, their systematic study has been intractable due to the reliance on manual extraction. To unlock this potential, we introduce Poly2Graph: a high-performance, open-source pipeline that automates the mapping of 1-D crystal Hamiltonians to spectral graphs. Using this tool, we present HSG-12M: a dataset containing 11.6 million static and 5.1 million dynamic Hamiltonian spectral graphs across 1401 characteristic-polynomial classes, distilled from 177 TB of spectral potential data. Crucially, HSG-12M is the first large-scale dataset of spatial multigraphs -- graphs embedded in a metric space where multiple geometrically distinct trajectories between two nodes are retained as separate edges. This simultaneously addresses a critical gap, as existing graph benchmarks overwhelmingly assume simple, non-spatial edges, discarding vital geometric information. Benchmarks with popular GNNs expose new challenges in learning spatial multi-edges at scale. Beyond its practical utility, we show that spectral graphs serve as universal topological fingerprints of polynomials, vectors, and matrices, forging a new algebra-to-graph link. HSG-12M lays the groundwork for data-driven scientific discovery in condensed matter physics, new opportunities in geometry-aware graph learning and beyond. Condensed_Matter/cond-mat.other_(Other_Condensed_Matter) https://arxiv.org/abs/2604.11870 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11870v1 Announce Type: new Abstract: Programmable arrays of neutral Rydberg atoms are one of the leading platforms today for scalable quantum simulation and computation. In these systems, the dipole-dipole interactions between the individual atoms, or qubits, typically result in binary -- i.e., two-body -- couplings. In this work, we develop an experimentally accessible scheme for engineering three-body interactions in Rydberg lattices. Such strong three-body couplings can fundamentally modify the underlying physics compared to systems with only two-body interactions: we demonstrate this, in particular, by systematically investigating the effective many-body Hamiltonian and its emergent quantum phases. This capability paves the way for the quantum simulation of a broader class of correlated models of condensed matter and high-energy physics. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.12030 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12030v1 Announce Type: new Abstract: We present a kinetic description of superfluid currents in ring-shaped Bose-Einstein condensates based on the Wigner phase-space formalism. Starting from the Gross-Pitaevskii equation in a toroidal geometry, we derive a Vlasov-type equation for the angular Wigner function, in which the mean-field interaction generates an effective force proportional to the density gradient. Within this framework, we obtain the dispersion relation of collective modes and recover the Bogoliubov spectrum in the long-wavelength limit. We show that the Landau criterion for superfluidity can be interpreted as the absence of resonant phase-space trajectories satisfying the condition \(\omega = q v_\ell\). In a ring geometry, the quantization of angular momentum leads to a discrete set of velocities, which suppresses the availability of resonant states and strongly inhibits Landau damping. In contrast, in the continuous limit \(R \to \infty\), the spectrum becomes quasi-continuous and the standard Landau damping mechanism is recovered, establishing a direct connection between kinetic resonances and the energetic criterion for superfluidity. We further analyze the role of Bogoliubov depletion by considering a finite-width angular momentum distribution. Although resonant states formally exist in this case, we show that, for flow velocities below the sound velocity, the phase-space distribution does not provide the gradients required for energy transfer, and the superfluid current remains dynamically stable. Our results provide a unified phase-space interpretation of superfluidity, highlighting the role of angular momentum quantization and the structure of the distribution function in determining the stability of persistent currents. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.12204 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12204v1 Announce Type: new Abstract: We describe a simple and compact experimental setup for optical tweezer arrays of 87Rb atoms. This setup includes a compact vacuum system, a single cooling laser, a simple tweezer laser, and a flexible control system. The small vacuum system with only 40 cm length takes advantage of the high atomic flux two-dimensional magneto-optical trap (2D MOT) while maintaining a low background pressure in the 3D MOT chamber ensuring sufficient lifetime of the trapped atoms. Atom number of the laser cooled sample of 2e7 and temperature of 92 uK is achieved. The flexible control system with real-time waveform generator modules (RWG) provides precise control of all the RF devices, and enables real-time feedback control of both the global and individual beams in optical tweezer arrays. An optical tweezer array with 25x25 homogeneous traps is demonstrated. This simple and compact demo setup makes it more accessible to experimental quantum physics. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.12475 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12475v1 Announce Type: new Abstract: We provide a fully analytical derivation of Anderson's orthogonality catastrophe for the one dimensional Fermi polaron integrable model, describing a system of $N$ spin-up fermions, with fixed density $n=N/L$, interacting with a single spin-down fermion via an attractive contact potential. The proof combines the determinant representations of the norm of the many-body wave function and of its scalar product with the noninteracting ground state, obtained from the Bethe ansatz solution, with the special properties of Cauchy matrices. We derive the leading asymptotics of the two determinants in the thermodynamic limit and show that the quasi-particle residue $Z$ decays algebraically, $Z=W N^{-\theta}$. We confirm that the Anderson exponent $\theta$ is equal to $2\delta_F^2/\pi^2$, where $\delta_F$ is the Bethe-ansatz phase shift at the Fermi edge. The prefactor $W$ is obtained numerically as a function of the interaction parameter. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.12063 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12063v1 Announce Type: cross Abstract: The puzzle of "sticky collisions," in which molecular collision complexes exhibit long lifetimes, remains an unresolved mystery. A central challenge is that traditional close-coupling calculations remain limited by the vast computational cost needed to take into account all the degrees of freedom involved in the collision. In this work, we propose a statistical model designed to simulate close-coupling calculations, with the goal of collecting statistics about reasonable lifetimes of collision complexes. To do so, we numerically sample resonances using random matrix theory and utilize results from quantum defect theory to calculate scattering properties and lifetimes. We find that in the limit of dense resonances, our theory agrees well with the Rice-Ramsperger-Kassel-Markus (RRKM) prediction, whereas in the limit of sparse resonances, the physics is governed by threshold behavior rather than resonant effects. By comparing these predictions to experimental results in two limits, we argue that close-coupling calculations alone may be insufficient to resolve the issue of long lifetimes. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.12448 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12448v1 Announce Type: cross Abstract: Neutral-atom arrays offer a promising path for quantum simulation, yet the potential of fermionic $^{40}$K remains largely constrained by state-dependent light shifts that degrade cooling and detection fidelities. This problem can be resolved by working at a magic wavelength, where the differential light shift vanishes. We report the first experimental determination of the magic wavelength for the D1 transition in fermionic $^{40}$K at 1227.54(3) nm. Using in-trap loss spectroscopy in a wavelength-tunable optical tweezer, we map the differential AC Stark shift across a range of trapping powers and wavelengths. By converting these shifts to differential scalar polarizabilities, we find excellent agreement with relativistic all-order calculations. Benchmark measurements at 1064.49 nm further reveal the significant intensity-sampling systematics that plague standard trapping wavelengths, contrasting with the "mechanically clean" environment provided by the magic condition. Our results provide an important step toward high-fidelity in-trap D1 cooling, fluorescence imaging, and light-assisted loading, establishing a robust path toward scaling fermionic neutral-atom arrays for quantum information science. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.13027 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.13027v1 Announce Type: cross Abstract: Many-body cages have very recently emerged as a general route for nonergodic behaviour in quantum matter. Here, we show that new types of many-body cages can be engineered in Floquet circuits with the potential to realize novel nonequilibrium quantum states. For that purpose, we first identify an explicit, general construction of Floquet circuits capable of hosting many-body cages. We then present a generic strategy to engineer and structure Floquet many-body cages. We demonstrate the developed scheme for the quantum hard disk model as a generic constrained model system, realizable for instance in Rydberg atom arrays. We construct Floquet circuits yielding Floquet many-body cages with topological properties and $\pi$-quasienergy modes, implying `time crystalline' spatiotemporal order. Our results can be directly extended to general quantum circuits, thus providing a new tool to engineer nonequilibrium behaviour in driven systems. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2509.04635 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2509.04635v2 Announce Type: replace-cross Abstract: We present a scheme for laser cooling and magneto-optical trapping of the Group IV (a.k.a. Group 14 or tetrel) atoms silicon (Si), germanium (Ge), tin (Sn), and lead (Pb). These elements each possess a strong Type-II transition ($J \rightarrow J' = J-1$) between the metastable $s^2p^2 \,^3P_1$ state and the excited $s^2ps'\, ^3P_0^o$ state at an accessible laser wavelength, making them amenable to laser cooling and trapping. We focus on the application of this scheme to Sn, which has several features that make it attractive for precision measurement applications. We perform numerical simulations of atomic beam slowing, capture into a magneto-optical trap (MOT), and subsequent sub-Doppler cooling and compression in a blue-detuned MOT of Sn atoms. We also discuss a realistic experimental setup for realizing a high phase-space density sample of Sn atoms. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2602.04593 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2602.04593v2 Announce Type: replace-cross Abstract: We investigate the emergence and detection of Hawking radiation (HR) in a 1D chiral spin chain model, where the gravitational collapse is simulated by a sudden quantum quench that triggers a horizon-inducing phase transition. While our previous work Jaiswal [2025] established that this model mimics BH formation conditions even when the Hoop conjecture is seemingly violated, we here focus on the resulting stationary radiation spectrum and its detectability. By mapping the spin chain dynamics to a Dirac fermion in a curved (1 + 1)-dimensional spacetime, we analyze the radiation using two complementary approaches: field-theoretic modes and operational quantum sensors. First, using localized Gaussian wave packets to model realistic detectors, we find that the radiation spectrum exhibits deviations from the ideal Planckian form, analogous to frequency-dependent greybody factors, while retaining robust Poissonian statistics that signal the loss of formation-scale information. Second, we introduce a qubit coupled to the chain as a stationary Unruh-DeWitt detector. We demonstrate that the qubit functions as a faithful quantum sensor of the Hawking temperature only in the weak-coupling regime, where its population dynamics are governed solely by the bath spectral density. In the strong-coupling limit, the probe thermalizes with the global environment, obscuring the horizon-induced thermal signature. These results provide a clear operational protocol for distinguishing genuine analog HR from environmental noise in quantum simulation platforms. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.07373 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.07373v2 Announce Type: replace-cross Abstract: Clusters of co-rotating vortices on compact fluid domains exhibit a simple collective dynamics, combining coherent global rotation with a slow breathing of the cluster size. In this work, we investigate an analytically tractable model of vortex interactions on a doubly periodic inviscid fluid domain, based on an exact representation in terms of the Schottky--Klein prime function and its $q$-representation. The two-vortex problem reduces to a single complex degree of freedom, from which explicit expressions for the orbital rotation frequency and dipole translation velocity are obtained. Building on this framework, we derive a small-cluster expansion that reveals a universal decomposition of the dynamics into planar interactions, isotropic torus corrections, and geometry-induced anisotropic modes. At leading order, the collective dynamics admits a description in terms of a single complex quadrupole moment: its real part governs corrections to the rotation rate, while its imaginary part controls the slow breathing of the cluster. These predictions are quantitatively confirmed by direct numerical simulations, establishing a reduced description of vortex clusters on the flat torus and compact fluid domains. Condensed_Matter/cond-mat.quant-gas_(Quantum_Gases) https://arxiv.org/abs/2604.12098 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12098v1 Announce Type: new Abstract: Multiscale periodic metamaterials have been designed for numerous applications, such as impact absorption, acoustic cloaking, photonic band gaps, and mechanical logic gates. This prior work has focused on optimizing mesoscale structure for desired bulk isotropic properties. In contrast, we seek to develop materials with highly anisotropic elastic properties. To quantify elastic anisotropy, we introduce two rotationally invariant, normalized quantities that characterize the anisotropic response to shear and compression, respectively, $A_G$ and $A_C$. We find that typical crystalline solids possess average elastic anisotropy $\overline{A}_G \approx 0.15$ and $\overline{A}_C \approx 0.09$. Compared to atomic crystals, jammed granular materials can attain elastic anisotropies that are several orders of magnitude larger. Since grain rearrangements reduce anisotropy in granular materials, to preserve strong elastic anisotropy, we design tessellated granular materials that consist of multiple connected grain-filled voxels, which limit rearrangements and enable highly anisotropic elastic properties. Bulk granular packings with $N$ grains prepared at pressure $p$ have maximal anisotropy for $pN^2\sim1$ and become isotropic in the large-$pN^2$ limit. We show that homogeneously tessellated granular systems can inherit the elastic response of the constituent voxel configurations with elastic anisotropy up to $100$ times that of crystalline compounds over a range of $pN^2$. We show further methods to tune the elastic anisotropy of tessellations by designing heterogeneously patterned voxel configurations and tessellations that allow large boundary deformations. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.12107 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12107v1 Announce Type: new Abstract: We use a minimal model for a dense suspension undergoing thickening and thinning to investigate microstructural changes in 2d simulations. Our simulations show that in steady flow the contact network contains distinct building blocks which are clearly signaled by sharp peaks in the radial distribution function, similar to what is observed in granular jamming. These structures {deform} during thinning. Non-Gaussian stress fluctuations that only emerge during thickening are associated to power law tails in the distribution of local contact forces, which tend to emerge when the flow-induced building blocks form large spanning assemblies. The subset of the contact network characterized by strong contact forces and connectivity large enough to be rigid or over-constrained is increasingly likely to percolate as the system starts to thicken, and to percolate over larger strain windows during thickening. The tendency of these structures to span the sample and to persist is dramatically reduced during thinning, where instead their deformation allows for a more homogeneous spatial redistribution of contact forces, significantly reducing the fluctuations of the macroscopic stress over time. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.12930 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12930v1 Announce Type: new Abstract: Organelle patterning and its heritability remain central mysteries in cell biology, highlighting the fundamental tension between genetic inheritance and self-assembly. Here, we explore the nonequilibrium assembly and size control of the Golgi complex and endosomes, amid a continuous flux of membrane traffic, within a stochastic framework of mechanochemical fusion-fission cycles that violate detailed balance. Using a dynamical systems approach, we identify distinct, robust regimes, ranging from fixed points to limit cycles with definite phase relations. We identify these dynamical regimes with diverse phenotypes, from stable cisternae to periodic, cell-cycle-dependent dissolution/reassembly to cisternal progression. We analyse its dynamic response to systematic perturbations or driving protocols and make definite predictions that may be tested experimentally. Our analysis reveals that the two competing models of Golgi organization-vesicular transport and cisternal progression - are, in fact, two phases of the same underlying nonequilibrium process. Finally, our framework offers a strategy for controlling cisternal chemical identity and number and by modulating the interplay between glycosylation enzymes and membrane fission-fusion dynamics. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.12938 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12938v1 Announce Type: new Abstract: Slender magnetic elements provide a versatile platform for programmable shape-morphing under remote magnetic actuation. However, a general and physically interpretable framework for the inverse design of a `magneto-elastica' under prescribed boundary conditions remains lacking. In this work, we develop an explicit analytical formulation for the inverse design of a magneto-elastica based on the integral form of the moment equilibrium equations. This approach yields direct constraints on the admissible curvature and rotation fields, enabling a systematic characterization of the feasible design space. We identify the key dimensionless parameters that govern the competition between magnetic torques and elastic restoring moments and show that the applied boundary conditions are an essential ingredient. We obtain closed-form solutions for the beam tapering profiles required to generate desired actuated shapes in the cases of clamped--free and clamped--clamped configurations; in the latter case, this includes analytical expressions for the boundary reactions. The formulation recovers the classical inverse elastica in the absence of magnetic fields and reveals a linear scaling between curvature deviation and magnetic mismatch. A tessellation strategy based on stiffness tailoring is further proposed for the design of discretized morphing surfaces. The theoretical predictions are validated against discrete elastic rod simulations and experiments across representative geometries. This work establishes a consistent analytical framework for the inverse design of a magneto-elastica and provides new insight into magnetically-induced shape programming in slender structures. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.11953 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11953v1 Announce Type: cross Abstract: Entropy is one of the key thermodynamic variables reflecting changes in the state of matter. Unlike other thermodynamic variables, it is well-defined also for nonequilibrium steady states through its relation to information. Applying this relation to physical systems is an ongoing challenge, as it requires knowledge of microscopic high-dimensional continuous distributions which is generally unattainable. A set of new approaches for the measurement of entropy in nonequilibrium steady or absorbing states have been developed and successfully applied to identify dynamic structures and transitions in diverse systems, ranging from jammed packings to swarming bacteria. We briefly review these approaches, emphasizing why applications to physical systems, including those out of equilibrium, is substantially different from the general statistical challenge of entropy estimation and inference. We point at promising current and future directions. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.12003 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12003v1 Announce Type: cross Abstract: Two-dimensional tsumoite (BiTe), a polymorph of Bi2Te3, has emerged as a promising candidate for nonlinear photonic devices owing to its strong spin-orbit coupling, tunable bandgap, and high carrier mobility characteristics. This work presents a thorough examination of the third-order nonlinear optical response of BiTe dispersions using spatial self-phase modulation (SSPM) spectroscopy. The nonlinear refractive index (n2) and third-order nonlinear susceptibility are quantitatively derived from the diffraction ring patterns, demonstrating third-order nonlinear susceptibility values, similar to or surpassing those of advanced 2D materials. The temporal development and distortion of the SSPM rings are examined using the wind-chime model, and thermal factors influencing the SSPM pattern are analyzed. First-principles electronic band structure studies reveal that the elevated nonlinear susceptibility arises from band dispersion. Direct correlation between carrier transport and third-order nonlinear susceptibility is established. Utilizing these qualities, all photonic devices, including a photonic isolator based on a 2D BiTe-2D hBN heterostructure, are depicted to show asymmetric propagation. A photonic information converter and a logic gate are designed using the cross-phase modulation technique. These findings establish 2D BiTe nanostructure as a formidable nonlinear optical platform for advanced photonic signal processing and integrated photonic applications. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2510.15856 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2510.15856v2 Announce Type: replace Abstract: Many small animals, particularly insects, use power-amplification to generate rapid motions, such as jumping, that would otherwise be impossible given the standard power density of muscle. A common framework for understanding this power amplification is Latch-Mediated, Spring Actuated (or LaMSA) jumping, in which a spring is slowly compressed, latched in its compressed state and the latch released to allow jumping. Motivated by the jumps of certain insect larvae, we consider an external latching mechanism via adhesion to a substrate that is quickly released for jumping. We show that the rate at which this adhesion is lost is crucial in determining the efficiency of jumping and, indeed, whether jumping occurs at all. As well as showing how release rate should be chosen to facilitate optimal jumping, our analysis underscores the importance of the interaction between latch-release dynamics and the elastic deformation of the jumper for power amplification, thereby providing new insight into post-latch jumping control. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2601.02291 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2601.02291v2 Announce Type: replace Abstract: We investigate the angle of repose ${\theta}_r$ of dense suspensions of colloidal silica particles ($d = 2$ $\mu m$ to $7$ $\mu m$) in water-filled microfluidic rotating drums experiments, to probe the crossover between the thermal (colloidal) and athermal (granular) regimes. For the smallest particles, thermal agitation promotes slow creep flows, and piles always flatten completely regardless of their initial inclination angle, resulting in ${\theta}_r = 0$. Above a critical particle size, piles of colloids stop flowing at a finite angle of repose, which increases with particle size but remains below the minimal value expected for athermal frictionless granular materials: $0 < {\theta}_r < {\theta}_{ath} \approx 5.8{\deg}$. We quantify the arrest dynamics as a function of the gravitational P\'eclet number $Pe_g$, which characterizes the competition between particle weight and thermal agitation. Our measurements are consistent with a recent rheological model [Billon et al., Phys. Rev. Fluids 8, 034302, 2023], in which the arrested state stems from a crossover between glass and jamming transitions as the granular pressure in the pile increases relative to the thermal pressure. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.00145 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.00145v2 Announce Type: replace Abstract: We derive a retained-spin micropolar hydrodynamic closure from the Boltzmann--Curtiss equation using a generalized Chapman--Enskog construction in which the local mean spin is retained as a quasi-slow variable. Starting from the one-particle kinetic balance identities and the corresponding exact coarse-grained finite-size balances for mass, linear momentum, and intrinsic angular momentum, we keep the collisional-transfer contribution to the antisymmetric stress explicit in the spin balance, decompose the first-order source into irreducible scalar, axial, and symmetric-traceless sectors, and show explicitly how the standard micropolar constitutive structure with coefficients $(\eta,\xi,\eta_r,\alpha,\beta,\gamma)$ emerges. This decomposition makes clear that the one-particle kinetic stress contributes only to the symmetric stress, whereas the rotational viscosity belongs to a collisional-transfer channel. For perfectly rough elastic hard spheres, we further obtain explicit dilute-gas estimates for the rotational viscosity $\eta_r$ from homogeneous spin relaxation and for the transverse spin-diffusion combination $\beta+\gamma$ from a transport-relaxation calculation. Targeted event-driven molecular-dynamics simulations are used as a posteriori checks: expanded homogeneous-spin density and roughness sweeps support the predicted $n^2$ and $K/(K+1)$ trends for $\eta_r$, while finite-$k$ transverse runs provide a qualitative diagnostic of the retained-spin response. The result is a self-contained derivation and coefficient-level estimate of retained-spin micropolar hydrodynamics that clarifies which parts of the closure are exact balance-law statements, which are first-order generalized Chapman--Enskog results, and which remain controlled rough-sphere estimates. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.11219 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11219v2 Announce Type: replace Abstract: The stretching and pinch-off of a liquid bridge is a simple way to probe when a suspension of particles stops behaving as a continuum. In this study, we consider density-matched suspensions of rigid nylon fibers with aspect ratios (length over diameter) ranging from 2 to 84, and volume fractions $\phi$ spanning the dilute to dense regimes. High-speed imaging of pendant-drop breakup reveals three successive regimes, as previously observed for spherical particles: an equivalent-fluid regime at early times, a dislocation regime corresponding to the separation of the rods, and a final regime controlled by the interstitial liquid once the neck is devoid of rods. The thresholds between these regimes follow the previously proposed scaling for spherical particles, in which the rod length, rather than the rod diameter, is used as the relevant discrete scale. In the equivalent-fluid regime, pinch-off also leads to an effective extensional viscosity that increases with both volume fraction and aspect ratio. This viscosity is not equal to the shear viscosity measured in a parallel-plate rheometer, but both sets of data are well described by Mills' law using a critical volume fraction $\phi_c$. Finally, the critical volume fraction $\phi_c$ decreases monotonically with the aspect ratio and is well captured by an empirical law. These results show that pinch-off is a sensitive probe of continuum breakdown in anisotropic suspensions and that, for rigid rods, the rod length controls the onset of heterogeneous thinning. Condensed_Matter/cond-mat.soft_(Soft_Condensed_Matter) https://arxiv.org/abs/2604.12101 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12101v1 Announce Type: new Abstract: Mott physics - the interplay between itinerancy and localization of electrons - is undergoing a paradigm shift from the binary "bandwidth - filling" tuning framework to an intertwining of geometric, topological, and fractionalized degrees of freedom. Based on a series of breakthroughs in 2024 - 2025, this paper proposes five pioneering discoveries: (1) Prediction of the golden-ratio scaling of quantum metric fluctuations near the Mott critical point, supported by functional renormalization group arguments and DMRG numerical verification (phi = 0.618 +/- 0.005); (2) Establishment of a correspondence between the denominator q of fractional Chern insulator charge and the subgroup index of the quantum geometry group, predicting that allowed q values follow the Fibonacci sequence {2,3,5,8,13,...} with specific material realizations; (3) Proposal of the Provability Hierarchy Theorem, classifying critical states like strange metals as "true but unprovable" QMA hard problems, establishing a rigorous connection to the complexity of the Consistency of Local Density Matrices(CLDM) problem; (4) Prediction of interference oscillations in the nonlinear Hall conductance within the pseudo gap phase, induced by geometric phase differences, supported by tight-binding numerical simulations; (5) Unveiling the quantum geometric tensor as a unified descriptor of band geometry and topology. These findings provide an experimentally testable theoretical framework for understanding strongly correlated quantum materials. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12203 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12203v1 Announce Type: new Abstract: We investigate the localized-electron character of the Mott-insulating phase in A$_3$C$_{60}$ using a single-site multiorbital electron model coupled to anisotropic molecular vibrations (Jahn--Teller phonons). We apply the spherical-tensor formalism, a framework originally developed in nuclear physics, to analyze the electron--phonon-coupled ground-state multiplet. Focusing on multipole moments, we find that both the conventional electronic quadrupole moment and the lattice displacement associated with the molecular vibrations vanish, even though the degenerate ground-state multiplet implies the presence of quadrupolar degrees of freedom. By analyzing these degrees of freedom within the spherical-tensor framework, we introduce composite (two-body) quadrupole operators involving both electrons and phonons and study their parameter dependence numerically. Furthermore, using quasispin selection rules, we demonstrate that the composite quadrupole does not couple to either the conventional quadrupole or lattice-displacement operators, thereby distinguishing it fundamentally from standard quadrupolar degrees of freedom. In addition, we investigate the nature of the electron--phonon entanglement and characterize it from the viewpoint of angular momentum. Analysis of the entanglement spectrum reveals that the ground state consists of superpositions of multi-phonon states with angular momenta $L_{\rm ph}=2$ and $L_{\rm ph}=3$, formed through coupling to three-electron states with $L=1$ and $L=2$. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12249 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12249v1 Announce Type: new Abstract: We systematically investigate the electronic structures of americium (Am), curium (Cm), berkelium (Bk), and californium (Cf) in both the ambient-pressure double hexagonal close-packed (dhcp) and high-pressure face-centered cubic (fcc) phases, using density functional theory combined with embedded dynamical mean-field approach. Our results reveal that Am exhibits moderate correlation strength and localized 5f states dominated by jj angular momentum coupling scheme. In Cm and Bk, strong electron correlations drive the system into a localized regime, characterized by Hubbard band formation, large effective electron masses, and non-Fermi liquid behavior. Their magnetic ground states are governed by exchange interactions within an intermediate coupling scheme that shifts toward LS coupling. Remarkably, Cf reenters a jj coupling regime while exhibiting the strongest orbital-selective correlations among the series. Atomic eigenstate probabilities show moderate configurational mixing in Am, whereas Cm, Bk, and Cf maintain nearly fixed trivalent configurations, indicating localized 5f states. Compared with the dhcp phase, the fcc structure generally enhances correlation effects, as evidenced by wider Hubbard bandgaps and increased valence state fluctuation in Am. Analyses of kinetic energy, potential energy, spin susceptibility, and charge susceptibility further corroborate the progressive localization of 5f electrons and the emergence of orbital-selective correlations from Am to Cf. This work establishes a unified picture of 5f electron evolution across the Am-Cf series, elucidating the interplay between spin-orbit coupling, electron correlation, and crystal structure in heavy actinides and offering insights into their behavior under high pressure. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12360 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12360v1 Announce Type: new Abstract: The spontaneous Hall effect, corresponding to a zero-field anomalous Hall effect (AHE), is induced by symmetry breaking associated with ferromagnetism. Studies in recent years, however, have revealed that antiferromagnetic (AFM) states characterized by magnetic point groups that allow ferromagnetism can also break the relevant symmetries and induce AHE without a large net magnetization. Here, we report that the AFM system Ce$_2$PtGe$_6$ exhibits a pronounced spontaneous Hall effect. Single-crystal neutron scattering experiments demonstrate that Ce$_2$PtGe$_6$ exhibits a collinear AFM structure with a propagation vector $q=0$. The small net magnetization of $\sim 10^{-3}$ $\mu_B$/Ce indicates that the observed AHE arises from symmetry breaking inherent to its AFM structure. The anomalous Hall conductivity (AHC) reaches $300$ $\Omega^{-1}$cm$^{-1}$, which exceeds the intrinsic AHC of related compounds such as Ce$_2$CuGe$_6$ and Ce$_2$PdGe$_6$. This large AHC, most likely attributed to the large spin-orbit coupling of the Pt atoms, provides a platform for understanding the interplay between the Berry curvatures and localized $f$-moments with an AFM configuration. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12489 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12489v1 Announce Type: new Abstract: Triangular-lattice systems host a variety of ground states, ranging from quantum spin liquids to magnetically ordered phases, the latter of which can exhibit a sequence of magnetic phase transitions under applied magnetic fields. Here, we report magnetic and thermodynamic measurements, combined with powder and single-crystal neutron diffraction, on a high-spin, nearly isotropic Mn$^{2+}$ triangular-lattice system K$_2$Mn(SeO$_3$)$_2$. The compound undergoes long-range magnetic ordering below $T_\mathrm{N} \sim 4$~K in zero field. Contrary to expectations for an ideal Heisenberg system, the compound adopts an up-down-zero (UD0) magnetic structure down to the lowest temperature (0.05 K), rather than the commonly expected Y-type structure. This UD0 state is, however, highly sensitive to external magnetic fields. For fields applied along the $c$ axis, it is readily destabilized and replaced by the Y-type structure, followed by an up-up-down (UUD) phase corresponding to the 1/3 magnetization plateau. In contrast, when the field is applied within the triangular plane, the system evolves into a canted Y state at a higher critical field. These results reveal that weak anisotropy, though small in magnitude, exerts a strongly orientation-dependent influence, playing a key role in selecting the field-induced phases in this frustrated magnet. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12674 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12674v1 Announce Type: new Abstract: The Dzyaloshinskii-Moriya (DM) interaction has been considered essential for skyrmion formation, however, the discovery of skyrmion lattices (SkLs) in nominally centrosymmetric materials where the DM interaction is forbidden, such as Eu(Ga$_{1-x}$Al$_x$)$_4$, has challenged this established view. Recent structural investigations of Eu(Ga$_{1-x}$Al$_x$)$_4$ have further complicated this issue by revealing that the charge-density wave breaks local symmetry, theoretically allowing DM interaction. This raises a fundamental question: are the complex magnetic phases driven by the DM interaction or by alternative mechanisms? Here, using soft-x-ray angle-resolved photoemission spectroscopy, we determine the three-dimensional bulk electronic structure of Eu(Ga$_{1-x}$Al$_x$)$_4$, and elucidate the electronic origins of its rich magnetic orders. We directly observe an x-dependent Lifshitz transition leading to the emergence of a Fermi-surface pocket. Importantly, multiple nesting vectors derived from this pocket match the symmetries and periodicities of the multiple SkLs. Moreover, these nesting vectors can also account for other magnetic orders, such as the zero-field helical magnetism, suggesting a common electronic origin of the complex magnetic phases. These findings suggest that competing nesting-induced Ruderman-Kittel-Kasuya-Yosida interactions and their engineering can generate and control various SkLs and related topological spin textures. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12676 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12676v1 Announce Type: new Abstract: The interplay between real-space topology such as magnetic skyrmions and momentum-space topology characterized by topological surface states (TSSs) is predicted to realize novel phenomena and functionalities, yet materials hosting both topologies are scarce. Skyrmion-hosting helimagnet family EuGa$_2$Al$_2$ and EuAl$_4$ has been a prime candidate for such a dual-topology system, but conclusive evidence for its momentum-space topology has remained elusive. We provide this evidence by directly observing TSSs that stem from bulk Dirac nodal lines using high-resolution angle-resolved photoemission spectroscopy. These TSSs are exceptionally robust against various perturbations such as a 2$\times$1 surface reconstruction, a chemical change in the termination of the crystal surface, and the onset of helical antiferromagnetic order. Crucially, below the Neel temperature, we observe replica bands driven by the magnetic ordering. Moreover, we demonstrate clear surface-termination dependence of this magneto-topological coupling. Our findings establish Eu(Ga$_{1-x}$Al$_x$)$_4$ as a dual-topology material and offer a rare platform to explore and control the interaction between the two fundamental topological realms. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12754 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12754v1 Announce Type: new Abstract: Long-range interactions can fundamentally reshape the low-energy properties of low-dimensional quantum matter, altering both continuous symmetry breaking and topological phenomena. However, their impact on the quantum criticality separating these regimes remains poorly understood. We determine the ground-state phase diagram and critical properties of the spin-one Heisenberg chain with single-ion anisotropy and staggered antiferromagnetic power-law interactions, using matrix-product state (MPS) calculations complemented by high-order series expansions (pCUT+MC). Such long-range, non-frustrated interactions circumvent the Hohenberg-Mermin-Wagner theorem, thereby stabilizing continuous symmetry breaking (CSB) phases in direct competition with the Haldane phase. We map out the resulting phase diagram and analyze the entanglement entropy scaling behavior in the U(1) and SU(2) CSB phases, finding logarithmic corrections beyond the short-range, universal contributions expected from linearly dispersed Goldstone modes. We further characterize all critical boundaries through finite-size scaling of either the entanglement entropy or the staggered magnetization. In particular, the large-D-to-U(1)-CSB transition exhibits unconventional, continuously varying critical exponents as a function of the long-range decay exponent with a strong dependence on the imposed boundary conditions leading to distinct finite-size scalings for sufficiently long-range potentials. Remarkably, the Haldane-to-U(1)-CSB transition likewise displays unconventional quantum criticality with distinct continuously varying critical exponents. Our work positions this model as a target for near-term atomic platforms with tunable long-range couplings and exhibiting natural single-ion anisotropy, offering a minimal playground for exploring the interplay between long-range interactions, continuous symmetry breaking, and topology. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12761 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12761v1 Announce Type: new Abstract: Yang-Mills theory has extended well beyond its original role in describing the strong force and now emerges as an effective theory in condensed matter, ultracold atomic, and photonic systems. In these systems, the theory has been successful in explaining phenomena such as the spin-Hall effect, spin transport, and controlling the polarisation of light. Moreover, the ability to engineer and control synthetic non-Abelian gauge fields in these systems enables us to explore aspects of gauge dynamics inaccessible to high-energy experiments. In all the above mentioned cases, the state of the system evolves in an effective external Yang-Mills field. Thus, the study of test particle dynamics in such background fields is interesting in both the classical and quantum mechanical regimes. The background non-Abelian (color) gauge fields considered in this study are constant, and they generate uniform color magnetic fields or combined color electric and magnetic fields -- which are relevant configurations. Despite the apparent simplicity of these backgrounds, the coupled evolution of real space motion and internal color degrees of freedom results in rich, nontrivial behaviour that is qualitatively distinct from the electrodynamic (Abelian) case, such as unbounded trajectories in a constant color magnetic field. In particular, particle trajectories encode signatures of the underlying gauge sources. Finally, the classical dynamics presented in this paper serves as a precursor to the complete quantum mechanical treatment to follow. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12959 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12959v1 Announce Type: new Abstract: In this Letter we theoretically study physical properties of a model of heavy fermion $d-f$ hybrid. In the studied model two species of fermions have dispersions with different masses, one being much heavier than the other. Hybridization between the fermions at the crossing point of their dispersions doesn't open a true insulating gap leaving a heavy fermion $d-f$ hybrid at the Fermi level. As a result, our theoretical model qualitatively explains experiments on the low-temperature phase of the SmB$_6$. These are the saturation of the resistance, linear in temperature specific heat, and frequency dependence of the optical conductivity. Calculated optical conductivity shows a broadened peak at the twice the hybridization value as well as a low frequency tail. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.12975 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.12975v1 Announce Type: new Abstract: We study the dynamical spin and nematic correlations in the bilinear-biquadratic spin-1 chain in the critical phase hosting deconfined spinons. We demonstrate how spinon interactions can be directly probed in the presence of a magnetic field or a single-ion anisotropy. Our analytical predictions are supported by numerical matrix-product-state (MPS) simulations of the underlying microscopic model. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons) https://arxiv.org/abs/2604.11900 Wed, 15 Apr 2026 00:00:00 -0400 arXiv:2604.11900v1 Announce Type: cross Abstract: Programmable quantum hardware provides an emerging platform for exploring and controlling non-unitary quantum dynamics through measurement-based operations. In this work, we introduce feedback-directed circuit architectures that integrate spatially structured mid-circuit measurements with real-time conditional operations to steer the evolution of random dynamics, and perform their large-scale simulations (up to 100 qubits) on programmable digital quantum processors. By promoting measurement from a passive readout to an active control signal, these adaptive monitored circuits enable directional information flow and generate intrinsic asymmetry in random circuit simulations. We implement this framework on IBM superconducting quantum processors and observe robust, noise-resilient signatures of feedback-induced asymmetry distinct from the more well-known non-Hermitian skin effect. Our results establish feedback as a programmable resource for non-unitary control, opening new avenues for engineering measurement-based dynamics, non-equilibrium phenomena, and tunable open-system behavior on large-scale quantum hardware. Condensed_Matter/cond-mat.str-el_(Strongly_Correlated_Electrons)